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Arkady Leokum Answers Hundreds of Questions Hamlyn , We all know that flies ' carry disease. The fly is born and may spend most of its life around rubbish and germ-breeding areas. The housefly actually chooses moist decaying matter as a place to breed. HOW ARE FLIES BORN? The female lays the eggs, which are white and about 1.2 millimetres long. From each egg comes a slender, wormlike maggot. This is the feeding stage, or "larva", of the Hy . After five or six days, the maggot's skin thickens and becomes brownish. This begins "the pupal", or resting. stage. Five or six days later, the full-grown fl y bursts out of the pupal skin. The fiy is then as big as it will ever be, for big fli es do not grow from small ftie s. About ten da ys later, the fi y mates, and soon after the female lays from 100 to 150 eggs! Not all flie s breed like the housefly. Many kinds hatch their eggs in their bodie s, giving birth to living larvae. Some kinds lay eggs that are already at the pupal stage. Man is waging a constant hattle against the fly because it spreads disease germ s. The best time to kill the housefly is in the winter and the early spring. During the co ld weather, the fty hides away in dark , warm corners of buildings. When flie s are seen during the winter in well-heated buildings, they should be killed. At that time, flies are easy to catch because they are very hungry. ADULT Fe> • 1" EGGS LARVAE PUPAE The fly is an amazing and deadly creature. The fly spreads more death and suffering than an invading army. It does harm by spreading disease with its hairy feet and legs from the filth on which it feeds and in which it HOW CAN A FLY breeds. This little insect is wonderfully made. WALK ON THE CEILING 7 The housefly has two big brown eyes and each eye is made up of thousands of lenses. These two big eyes are called "compound eyes". The fly also has, on top of the head, looking straight up, three "simple eyes" that can be seen only through a magnifying glass. The feelers, or antennae, of the housefly are used as organs of smell, not of feeling. These antennae can detect odours at great distances. The mouth is made up of an organ that people call a tongue, but it is really all the mouth parts of an insect combined in one. This tongue is really a long tube through which the fly sucks juices. The body of the housefly is divided into three parts: the head, the middle section, or thorax, and the abdomen. Behind the two transparent wings are two small knobs that help the fly balance itself in flight. The thorax is striped and has three pairs of legs attached to it. The legs are divided into five parts, of which the last is the foot. The fly walks tiptoe on two claws that are attached to the underpart of the foot. Sticky pads under the claws allow the fly to walk upside down on the ceiling or anywhere else with the greatest of ease! It is because of these sticky pads and the hairs on the legs that the fly is such a carrier of disease germs. Did you know that the entire life of a housefly is spent within about one hundred metres of the area where it was born? 201 There are thou s and s of different species, or kinds, of bees. So their habits and ways orlife differ quite a lot. But probably the two things that we find most interesting about bees is how they produce honey, and how the "social" bees h~ve organized their life. In producing honey. a bee visits flowers, WHAT HAPPENS TO BEES IN WINTER 7 drinks the nectar, and carries it home in its honey sac. This is a baglike enlargement of the digestive tract just in front of, but separate from, the bee's stomach. The sugars found in neclar undergo chemical changes while in the bee's honey sac as the first step in changing nectar into hon ey. Before nectar becomes honey, the honey- bees remove a large part of the water by evaporation processes. Hone y stored by bumblebees in ce ll s called "honeypots" is almost as thin as neclar and will sour in a short time. Honey stored in the honeycombs by honeybees has so much water removed from the original nectar that it will keep almost for ever. What about the winter? In temperate region s, the young queen bumplebees pass the winter in holes they dig in well-drained sandbanks or in other suitable places. They are the only members of the colony that Bve through the winter! In the spring, each suryiving queen starts a new colony. The honeybees are luckier. They can adapt themselves to all extremes of climate. They have a social organization that is so very efficient and complicated that it has been compared to that of man . In the hive where they live. worker bees regulate the temperature with great exactness. They keep it at 34 degrees Centigrade where the young bees are being developed. During the winter, they do not let the colony temperature fall below 7 degree s. Honey stored in the hive is used as fuel by the bees. They have an efficient way of preventing the loss of more than a ve ry sma ll part of the heat they produce by consuming honey. HONEY SAC HONEY BEES IN HI VE TAPEWORM EARTHWORM Scientists find it difficult to define exactly what worms are. They may best be described as elongated, boneless animals, having an undersurface fitted for crawling. and a more or less definite head end. One other im- TO WHAT FAMILY DO WORMS BELONG? portant feature of worms is that they can be divided into two similar portions. their. right and left sides. So when you have something that fits this description, you have a worm. Worms vary in size from microscopic to about 12 metres long. They vary in colour from transparency to dark brown, green, and red. Worms form several distinct primary groups of animals. The most important of these are the flatworms; a group that includes the thread worms, roundworms, and hookworms; and the segmented worms. The flatworms have flattened bodie s. Each one contains both sexes within itself. Some of them are free Hving, others are parasites. Among the parasitic flatworms is the tapeworm. It usually lives in the intestines of back boned animals, such as man and dogs. The threadworms are a large group of threadlike worms, varying in size from hardly visible species to others a few metres long. Among the most dangerous worms are the pinworm, trichina, Guinea worm, and the common roundworm. They cause serious illness to man and several animals. The earthworms, with which we are most familiar, are among man's best friends. By burrowing into the soil, they loosen it for more effective growing of crops. 203 There is no other animal that man has fought with such energy for so long in so many places as the rat! There arc;: many species of animals called rats, and most of them are harmless and interesting animals. But there ARE RATS A PEST? are two common rats, the black rat and the brown rat, that have given rats a bad name. Why does man fight the rat? Each year rats ruin hundreds of millions of pounds worth of grain. They destroy eggs, poultry, song birds, and spoil food in homes and on ships. Fires are caused by rats gnawing matches, gas pipes, and insulated electric wires. House$ may be flooded when they gnaw through water pipes. They damage floors and furnishings. Finally, they spread diseases such as the fortunately rare bubonic plague. There are probably as many rats as people in the citie~ .> ofthe world. In the country, they actually outnumber human beings by three or four to one! They climb and burrow and live indoors or outdoors, in dry places or wet. They like vegetables best, but they will eat almost anything. And since they can live almost anywhere and increase so rapidly, they are hard to control. A female rat may have ten litters of young in a year, and the young are ready to produce more young in only four months! The black rat was originally a native of Asia Minor and the Orient but • reached Europe with Crusaders returning from Palestine in the Middle Ages. The brown rat originally inhabited the tree-less steppes of Central Asia and probably started emigrating in large numbers before Roman times. Like the black rat, it eventually reached all parts of the world by living in the holds of ships, and has proved itself to be one of the most adaptable animals ever known. Along with mice, another rodent which also lives wherever man does, rats have become popular pets. They are especially qred for this purpose and are not wild rats, although the basic colours and patterns of pet rats originate from wild specimens. White rats are actually albinos of brown rats. An albino of any animal is one which lacks normal pigmentation in its skin or hair. They are usually quite rare but man has specially bred albino rats for their "colour". Pet rats need to be kept in cages, but they require quite a lot of room and cages with a ramp leading to a second level are recommended. Of course it is best to use metal cages as rats will gnaw, their' way through wooden ones if they get bored or want to escape. They will live on almost anything, but pet rats are best fed on rolled or crushed oats mixed with a little bird seed. They will live for as long as two or three years. 204 An asp is simply a kind of snake. It belongs to a family of snakes called "vipers", which includes some of the deadliest poisonous snakes in the world. Some other snakes in this unpleasant group are: the rattlesnake, WHAT IS AN ASP? the water moccasin. the copperhead, the South American bushmaster, the poisonous adder of Europe. the chain viper of India, and the horned viper of Africa. The asp that is supposed to have killed Cleopatra was probably the homed viper of Africa. The poison, or venom, of such a snake destroys the capilJaries in the body so a person dies of internal bleeding. All vipers have thick bodies and fiat, triangular heads. Their poison fangs, which are located in their upper jaws, are really very long teeth. There is a tube or channel in these teeth which connects to the poison glands, or sacs, located just behind the eyes. When the snake wants to bite, it contracts the muscles of these sacs and the poison flows out through the fangs into the open wound which the snake has made by its bite. ]n a medium-sized snake, as much as half a teaspoon of this poison can be put into the victim at one time! Removing the fangs of such a snake does not do much good. This is because new fangs are always developing behind the old fangs. So they simply take the place of the removed fangs! The vipers are divided into two families: the true vipers, which are found only in Europe and parts of Africa, and the pit vipers, which are found in the Western Hemisphere and some parts of Asia. The most deadly of all vipers is the chain viper of India, which is often 1.5 metres long. By the way, vipers will not strike unless they are molested or are seeking prey. But it is still wise to stay away from them! 205 It all depends on what we mean by "deadly". Should we consider it to be the snake that kills the mos poisonous venom? WHAT IS THE DEADLIEST SNAKE? Some experts have called the king cobra the world's deadliest snake. And they give several reasons for this. It is the longest venomous snake in the world. Its venom is very powerful. And it is a snake that does not hesitate to attack. There have been cases of people dying in less than an hour after being bitten by a king cobra. Another candidate for "deadliest" is the tiger s nake of Australia. lts venom is one of the most potent known. But this s nake only has a limited amount of this venom. There is also a snake in India called the krait which belongs to this group . There are records to show that about 77 per cent of all people bitten by this snake die. The spectacled cobra ofIndia actually kills more people than any other kind, but less than IO per cent of those bitten would die if they received treatment in time. By the way. the largest snake in the world is not the deadlies t. This is the anaconda of South America. It can be as long as 9 metres. But this s nake is found in areas that are very hard to get to, so there may be even larger anacondas that have not yet been discovered. In the United Kingdom there is only one poisonous snake, the adder, which is found in most parts of the British Isles. but not in Ireland. To most of us, a snake is a snake. We know there are differences among them, hut we do not realize how great these differences are. The many differentspecies of snakes reproduce in many different ways. DO SNAKES LAY EGGS? There are many species of snakes, in- cluding rattlesnakes, copperheads, water snakes, and garter snakes, that do not lay eggs, but give birth to living young. And many produce quite a few young at one time. Some snakes have been known to have more than 75 young at one time! Then there is a big group of snakes that lay eggs. These eggs are usually deposited in hidden places such as under a rock or log, or in hollow stumps. The eggs are not the same shape as chicken eggs, but are a little longer and usually smaller. The eggs of the hull snake, however, and those of certain large snakes, are abo~t the size of a chicken egg. The shen of a snake's egg is tough and has a leathery quality. The number of eggs they lay depends on the species. The snake that lays the most eggs is probably the python. One Indian python was known to have laid 107 eggs at one time. The eggs are hatched by the heat of the sun or by decaying vegetable matter which gives off a natural heat. In so me cases, the snake guards the eggs by coiling about them . Since some snakes can lay 100 eggs at a time, who takes care of the young when the eggs hatch ? No one has to. All young snakes are able to care for them selves from the moment of hatching or birth! 207 If you have ever watched a snake move, there were probably two things about it that impressed you. The first, of course, was simply the mysterious ways in which a snake moves. You do not see any legs, the body does not DO SNAKES HAVE BONES? seem to have anything to push or pull it, and yet there it is, moving! And the second thing is that the body seems to "flow" along the ground. It does not seem to have a bone in its body!· The fact is, however, that a snake is simply full of bones! A snake has a sectioned backbone, and to this backbone are attached pairs of ribs. Some snakes have as many as 145 pairs of ribs attached to that very flexible backbone. Ball-and-socket joints attach the sections of the backbone to one another, and each rib to a section of the backbone. So great freedom of movement of that backbone and the ribs is possible. The tips of each pair of ribs are attached with muscles to one of the scales that are on the "stomach", or abdomen, of the snake. Because of this, a snake can move each one of these scales independently. When the snake moves one of these scales, that scale acts like a foot. Snakes also have bones in their heads and jaws. A snake can open his jaws very wide when it is swallowing its dinner. This is because all the bones around the mouth and throat are loosely attached so the mouth can be stretched very wide. In fact, most snakes swallow their catch with- out trying to kill it first. Later on they digest it. So, you see, snakes do have bones in their body, even though their slithery bodies look as if there's nothing solid in them! Just because snakes do not have legs now, does not mean they did not have them at sometime in their development. But how and why they came to lose their legs is not known to science. WHY DON'T SNAKES HAVE LEGS? Some experts believe that the ancestors of snakes were certain kinds of burrowing lizards. There are many kinds of such lizards today, and all of them have very small legs or no legs at all. In time, the legs disappeared altogether. And despite this, snakes are able to move and get along very well indeed. One of the most helpful things for them in moving are the belly scales that cover the entire undersurface of most snakes. 208 [...]... on their bodies, and their forelimbs became wings In time they learned to fly, and birds came into being Birds' feathers are the result of changes that took place in the reptile scales Other reptiles ceased to lay eggs and became mammal-like animals that gave birth to their young They also became warm-blooded and developed into true mammals The name "amphibian" comes from a Greek word which means "... its food, an ostrich will sometimes swallow large stones, bits of iron, and other objects! Ostriches are raised commercially for their beautiful plumes The cropping of the plumes does not harm the birds The first cropping may be done before the bird is a year old Each time it is done, the plumes will grow again 212 There are about 50 different kinds of birds of paradise, but they are all found in the... Caribbean right up to Florida It may be over II metres long and weigh more < /b> than 13 tonnes The other " safe" big shark is the basking shark It is the biggest fish of the North Atlantic, and is over 13 metres long It likes to bask in the sun with its back partly out of the water But the most dreaded of all fish is the great white shark, which is sometimes 12 metres long It definitely attacks human beings... attached to the breast· bone, bringing them closer to the centre of gravity Even the fact that birds are warm· blooded is a help, because cold·blooded creatures become sluggish in winter So you see, everything about the bird is "designed" to help it to fly! 215 The ability of certain birds to fly great distances and arrive "home", or at their destination, is one of the most remarkable things in nature... birds returning have been recorded passing the same locality on the same date in consecutive years Birds are able to navigate by means of the sun and stars, but how they do this has not yet been fully established 211 ., I r 4/ / Any way you look at it, the ostrich is a strange and remarkable bird It is the largest of living birds- but it cannot fly Its small wings are used for balance when it is running... other vertebrate animal (an animal with a backbone) There are many cases on record of such turtles having lived 100 years and longer, and there may be some that lived as long as 200 years! 2t9 If you've ever been fishing you probably feel that fish eat everything but what you use for bait! Little boys in towns often catch fish with a piece of bread on a bent pin Country boys use worms Trout fishermen use... MYNA BI RD There are a great many birds which can be taught to say a few words But the real "talking birds" can be taught to say long 'sentences! The best talking birds are parrots, mynas, crows, ravens, jackdaws, and certain jays According to the experts the best bird talkers WHAT BIRDS in the world are the African parrot and the myna CAN TALK BEST? bird of India Many people believe that the ability... these eggs have been found and measured Some of them are 33 centimetres long and 23 to 26 centimetres in diameter The shell of these eggs will hold about eight litres, and that's six times as much as an ostrich egg will hold, and nearly 150 times as much as a hen's egg will hold! The smallest eggs are produced by hummingbirds Some species of hummingbirds lay eggs that are only six millimetres in length... dives down into the sea to swim about BLUE WHALE • The biggest whale also happens to be the largest animal in the world It is the blue, or sulphur-bottom, whale, which may be more < /b> than 30 metres long and weigh 125 tonnes It may be found in all waters but is most WHAT IS THE common in the Pacific Ocean It belongs to the BIGGEST WHALE? group of whales known as "the whalebone whales" (the other is known... into the body of the oyster This is really a surgical operation requiring great care and delicacy, because the oyster must be kept alive The largest pearl found is said to have been 5 centimetres long and 10 centimetres round Because pearls are expensive, most of us buy artificial pearls The French make beautiful artificial pearls by taking hollow glass beads, lining them with a substance that comes from . for more Ihan 100,000,000 years. Some of the reptiles developed feathers on their bodies, and their forelimbs became wings. In time they learned to fly, and birds came into being. Birds'. pairs of ribs attached to that very flexible backbone. Ball-and-socket joints attach the sections of the backbone to one another, and each rib to a section of the backbone. So great. and ringed birds returning have been recorded passing the same locality on the same date in consecutive years. Birds are able to navigate by means of the sun and stars, but how they