The odorous house ant, Tapinoma sessile, is one of the species that commonly makes nests in people's kitchens, where their workers scavenge sweet or fatty foods, or foods rich with protein. They also eat insects. Outdoors, these hardy little ants may be found almost anywhere, but especially under rocks. Workers are less than 1/8 inch long. When squashed, these ants produce an unpleasant smell, hence the common name.