But evolution and common sense, she says, tell us otherwise.
"We know to a certainty that some animals feel profound sadness and grief, as well as joy," Barbara J. King, professor of anthropology at the College of William and Mary and author of "How Animals Grieve," told The Dodo.
"Some intriguing reports," King says, "raise questions about a tipping point between stress animals feel and possible acts of self-harm or suicide. It is true, though, that the issue of intent is very tricky in determining a conscious will for death."
Regardless, King says she's not sure how important it is to know whether or not animals kill themselves in the first place. "It is honestly less important to know whether or not animals commit suicide than it is to know that, when we humans harm animals in contexts ranging from the slaughterhouse to circuses and some zoos, from theme parks to biomedical laboratories, we cause terrible suffering, as we do when we destroy wild habitats."
Mainly, King says, "we need to work much harder to stop animal suffering."