Reading - Part 1

Read the text. Fill in each gap with ONE word. You must use a word which is somewhere in the rest of the text.

Hibernation

During the cold winter months, many warm-blooded animals need extra energy to stay warm, but the source of that energy - food - is scarce in (1). Some (2) migrate to warmer places to survive winter. Others, such as hedgehogs and bats, hibernate in a safe place such as a nest or cave. In true hibernation, the lungs breathe very slowly and the heartbeat occurs only every now and then. The body temperature also falls but will switch on again to stop the animal from freezing if the outside temperature drops below zero. Animals that hibernate stock up on extra food in the autumn to build up body fat so they can survive the winter months without (3). (4) can last several days, weeks or months depending on the species of animal and the time of year. Black Bear

American black bears sleep during the winter months, but their sleep is not as deep as the true hibernation of mice and bats. A (5) bear's body temperature drops and their heartbeat slows down but they can wake up quite quickly if they are disturbed. During the winter months they do not eat, drink or go to the toilet. Aestivation

Aestivation is similar to hibernation. Aestivation usually takes place during the summer months. Animals sleep during the hot, dry season to survive the intense heat and avoid damage from high temperatures. Desert (6) including lizards, frogs, insects and snails do this.