The simple answer is either they are stored in your memory or you forget them. But this question makes us ask a great number of other question. What is the difference between day-dreaming and the dreams we have when we are asleep? Can dreams foretell the future? How long do they really last? Do we have dreams in color or …

Every night the chimpanzee spends five minutes making its bed for the night. It bends two or three leafy branches together to make a platform quite high up in the trees. It curls up on its side with legs drawn up and soon falls asleep.

Butterflies, and moths as well for that matter, are very particular about laying their eggs. Most butterflies leave them on only one sort of plant because this is the plant that the newly hatched larvae, called caterpillars, will feed on. So the female butterfly will spend some time finding the correct plant (the foodplant) before laying her eggs. You might …

The sponge with which some people regularly soap themselves in the bath is really the skeleton of a particular type of natural sponge. Bath sponges are supported by a framework of a resilient, elastic material called ‘spongin’, and it is this that makes up the bathroom sponge. Bath sponges are found in warm shallow seas, and in various part of …

One of the reasons why the French wished to establish colonies in the New World was because some of them wanted to escape religious persecution at home. In 1562, a group of thirty French Protestants, let by Jean Ribault, landed at the mouth of the St John’s River in the Spanish territory of Florida (left). However, the Indians were hostile, …

Ooh, aah, ouch! People in ancient times must have yelped like this when they walked on rough ground without any shoes on. And it was probably the pain and discomfort that propelled them to cover their feet for protection. Footwear has a history which goes back many thousands of years, and has long been an article of prestige for people …

Rocks that were formed in the last 2,800 million years can be found in every continent, but rocks more than 3,500 million years old are extremely rare. Some rocks in the American Minnesota River valley and others in western Greenland have been dated at about 3,800 million years. The world’s oldest rocks, however, are probably in Australia, where, in 1983, …

Venus in the hottest of the Sun’s planets. Space probes have measured the temperature on its surface as a scorching 4600 C (9500 F). The reason is that Venus is surrounded by a dense atmosphere of carbon dioxide, which traps the Sun’s heat like a greenhouse. The coldest planet is distant Pluto, whose surface has a temperature of -2300 C …

About 2.15 per cent of the world’s water supply is frozen. Most of the ice is blocked in two great ice sheets, the largest blanketing most of Antarctica and the other in Greenland. Smaller ice caps occur on northern islands, including Iceland, Spitzbergen and various islands in northern Canada. Valley glaciers are smaller still. They are found on mountain slopes …

Our galaxy, vast island of stars though it is, is only one of millions of similar galaxies scattered throughout space as far away as we can see through cur telescopes. The nearer galaxies to our galaxy are two small satellite galaxies called the Magellanic Clouds. They can be seen only in the southern hemisphere, and look like pieces torn out …