Inside the wild ways many creatures make milk

Scientists once thought that milk production was a characteristic exclusive to mammals. The name is derived from the Latin word for “breast.”

But Benoit said scientists are finding that this isn't necessarily the case.

Everything from jumping spiders to penguins to some amphibians produce a milky, protein-rich secretion to feed their young. And while it doesn't share the same evolutionary origin, it has a similar function, Benoit said.

In his biology lab, he has studied insects such as beetle-mimic cockroaches that feed milk to their newborn babies.

“We usually call it a milk-like substance,” he told Smithsonian. “For all intents, it does the same thing, and even some of the proteins present are similar.”

Benoit said tsetse flies along with some ants and spiders, too, secrete a nourishing milk-like substance for their babies. And each species arrived at this survival strategy for raising babies independently, which demonstrates its benefits across the animal kingdom, he said.

Read the Smithsonian story.

Featured image at top: UC Professor Joshua Benoit holds up beetle-mimic cockroaches in his biology lab. Photo/Andrew Higley/UC Marketing + Brand