Peter Krupa

Scientists have observed chimpanzees fashioning spears out of sticks to use as hunting weapons:

Using their hands and teeth, the chimpanzees were repeatedly seen tearing the side branches off long straight sticks, peeling back the bark and sharpening one end, the researchers report in today’s on-line issue of the journal Current Biology. Then, grasping the weapon in a “power grip,” they jabbed into tree-branch hollows where bush babies — small monkey-like mammals — sleep during the day.

After stabbing their prey repeatedly, they removed the injured or dead animal and ate it.

“It was really alarming how forceful it was,” said lead researcher Jill D. Pruetz of Iowa State University in Ames, adding that it reminded her of the murderous shower scene in the Alfred Hitchcock movie “Psycho.” “It was kind of scary.”