They're just like family, only hairier

Orion remains oblivious to the spell he casts over his observers -- also primates, but this species clad in dusty hiking boots, safari wear and a thin coat of sweat. He doesn't notice when one of them, clutching a camera, breaks from the group and scrambles halfway up a tree to get a better shot.

Orion cares only about the ants.

Cocktail ants, to be precise. The creatures are nicknamed cocktail ants because the distinctively large end of the abdomen can be cocked over the thorax for protection.

With his right hand, Orion pushes a slender twig into the insects' nest buried in the bark; he clutches a set of spare twigs in his toes. Ants cling to this natural utensil as he pulls it from the nest -- only to be polished off by the chimpanzee, who punctuates his enjoyment with much lip smacking and the occasional passing of wind.

By the end of our three days at Mahale Mountains National Park in Tanzania, Orion feels like one of the family. So do the other chimpanzees that make up the 65-odd habituated animals that researchers from Kyoto University in Japan have studied for about 30 years.

My husband, Alan Feldstein, and I expected to see chimps in this remote area on the western border of Tanzania, East Africa. But we never dreamed we'd come to know them by name.

There is Gwekulo, the "spinster"; her limping gait suggests she may have broken a leg or pelvis and either become barren or been rejected by the males. Now she serves as nanny to the babies of other females. There is Opal, who has a bald spot on her forehead.

There is strong Alofu, the reigning alpha male, and wise Kalunde, "the King Maker," at 53 the oldest of the group and a former alpha. (A chimp's average life span is 50 to 60 years.) Kalunde did not suffer the rejection typical of most deposed alpha males. That's because he teamed up with Alofu's mother in negotiating Alofu into power.

Christina, another female, shamelessly flirts with Alan, showing off her squishy mouthful of figs.