Emory University:

In 2010, Emory biologist Jaap de Roode published the discovery that monarch butterflies use medicine to cure their offspring of disease. His lab revealed how, if infected with a parasite, the female butterflies prefer to lay their eggs on a species of milkweed containing higher levels of a toxic chemical. The caterpillars eat the milkweed, ingest the toxin, and reduce the parasite load in their bodies.

With that finding, de Roode joined the vanguard of scientists uncovering how animals treat themselves for diseases.

“We showed how even an insect with a teeny-tiny brain can medicate,” de Roode says. “From there it was a natural progression to the understanding that, in principle, any animal can do it.”

In his new book, “Doctors by Nature: How Ants, Apes and Other Animals Heal Themselves,” de Roode explores the growing field of animal self-medication. He interviews scientists around the globe and describes research into how animals from ants to apes, birds to bears — even family dogs and cats — use various forms of medicine.

Scientific evidence of animal medication goes back to the 1980s when studies showed how wild chimpanzees chewed bitter plants or swallowed rough leaves to rid themselves of worms.

Some scientists began arguing that animal self-medication requires great cognitive ability, memory and learning behaviors and was likely restricted to higher-order primates. That stance soon toppled with evidence of self-medication in a range of primates and other mammals.

De Roode’s monarch butterfly discovery opened the door to a whole new level of understanding. It joined a handful of other published examples of insects tapping into nature’s medicine kit, such as wood ants that collect pieces of resin and bring them to their nests to reduce microbial infections. [Continue reading…]