In the past, many scientists believed that only mammals and birds could feel or think in complex ways. Reptiles, fish, and insects were seen as simple creatures that reacted purely on instinct. But ...

The more we study sentience among nonhuman animals (animals) the more species are added to the sentience arena—the biodiversity of sentience is forever growing—and ethical questions about pain and ...

Teeth first evolved as sensory organs, not for chewing, according to a new analysis of animal fossils. The first tooth-like structures seem to have been sensitive nodules on the skin of early fish ...