Many of the most flexible examples of tool use in animals come

from primates (the order that includes humans, apes, and monkeys).

For example, many wild primates use objects to threaten outsiders. And 【M1】________

there are many examples of tool use by the other mammals, as well as by 【M2】________

birds and other types of animals.

Tools are used by many species in the capture or preparation of

food. Chimpanzees use sticks and poles to bring up ants and termites (白 【M3】________

蚁) from their hiding places. Among the most complex tool use

observing in the wild is the use of stones by Ivory Coast chimpanzees to 【M4】_________

crack nuts open. They select a large flat stone as anvil (a heavy block on 【M5】_________

which to place the nuts) and a smaller stone as a hammer. Stones

suitable for use as anvils are not easy to find, but often a chimpanzee 【M6】_________

may carry a haul of nuts more than 40 meters to find a suitable anvil.

The use of tools in chimpanzees is especially interesting while these 【M7】_________

animals sometimes modify tools to make them better suited their 【M8】_________

intended purpose. To make a twig more effective for digging out

termites, for example, a chimp may first strip it of its leaves.

Surprisingly, there is also a species of bird that use sticks to probe 【M9】_________

holes in the search for insects. One of the species of Galapagos finch

(雀类), the woodpecker finch, picks up or breaks off a twig, cactus

spine, or leaf stem. This primitive tool is then held in their beak and 【M10】________

used to probe for insects in holes in trees that the bird cannot probe

directly with its beak. Birds have been seen to carry twigs from tree to

tree searching for prey.

【M1】