A swallow builds its nest inside farm buildings and on ledges in old chimneys. The nest is made of mud, straw and saliva, with feathers and wool to line the inside. It takes a pair of swallows up to several weeks to make the saucer-shaped nest in the rafters of a barn. Swallows starts arriving in Europe at the end …

Leeches, which are rather slimy worms and vary in length from an inch to several inches, have two suckers, a big one at the rear and a smaller one at the mouth end. They have powerful muscles, which enable them to expand and contract their bodies. This makes them excellent swimmers. They can also use their suckers to crawl on …

A bee keeps its sting at the end of its abdomen. At tip of a bee’s abdomen is a shaft where its stinging thorn is to be found. It can sting several times, but once it leaves the thorn in its victim’s flesh it will not be able to sting again. It is not true to say that a bee …

We expect you know there are some active volcanoes either today or in the very recent past, because when one erupts it always makes the headlines in the newspapers for example, we have already mentioned the eruption of Mount St Helens, and, of course, Mount Etna in Sicily is still active as are some of the volcanoes on the Hawaiian …

A whelk is a kind of sea-snail. It eats clams, worms, barnacles and smaller snails. The female lays her eggs in hard capsules. These are arranged in clusters of string and attached to rock, wood, and shells. Fishermen use whelks as bait. They catch the whelks by setting traps and baiting them with crabs. Whelks are eaten by cod and …

You probably know that tigers live in jungles, and you may know that some come from India, but do you know that there eight distinct races of tiger scattered throughout Asia? The tiger ranges from Iran to Turkestan, Mongolia, Siberia and Korea. It is also found throughout India, Tibet, China, Thailand and Indo-China. Some even reach as far as the …

The soft, absorbent, natural sponges used in baths are the skeletal remains of a marine animal. Biologists once thought sponges were plants. This seemed natural as sponges have no special shape and attach themselves to one spot on the sea-bed like plants. Also, they have no limbs, mouths or internal organs. Today, however, they are classified as animals. The familiar …

A spider does not have a readymade web. She spins one. If you are lucky, you may be able to watch the female spider doing this. The material that makes the thread for the spider’s web is a liquid, which she produces from tiny spinning tubes. These spinning tubes are to be found on small lumps on her body, known …

Atlantic salmon, called the greatest game fish in the world by sportsmen, spawn in the fresh water streams of Europe, from Portugal to northern Russia, and in the streams of the eastern seaboard of North America, from Maine up to northern Canada. They are found also in the streams of Greenland and Iceland. Pacific salmon, of which there are several …

We all know that birds build nests. Some find trees the most convenient. Others prefer hedges, the eaves of roofs, chimney pots, rocky ledges or holes in trees. But what does a bird do that can neither fly nor swim? Living on the dry, open plains of eastern and southern Africa, the ostrich takes no pains to hide its nest. …