Do platypuses really sweat milk?

In a sense, all mammals sweat milk. The milk glands are modified sweat glands, so milk is just special sweat that has been enriched with antibodies and nutrients. read more

The milk glands are modified sweat glands, so milk is just special sweat that has been enriched with antibodies and nutrients. This fact is not obvious to people and other placental and marsupial mammals because we have evolved a special structure called a"nipple" that delivers this special sweat to the infant. Platypuses, however, don't have nipples. read more

Mammary glands in mammals really are heavily modified sweat glands. In the more primitive Monotremes, which includes the platypus, there are mammary glands but no teats. When lactating, the mother just excretes milk out of pores in the skin and the young licks it off the mother's abdomen. read more

They do give milk to their babies, but unlike almost all other mammals they don’t have nipples. Instead, they essentially sweat out their milk from pores along their stomachs. The platypus has a bill kind of like a duck, but it’s really more of a hard snout. read more

All mammals do not sweat milk, only female mammals. Platypuses and echidnas have"lactating patches" that ooze milk. They are the only egg-laying mammals, which means that egg laying is not a criteria that defines mammals but producing milk is. Note that the root of"mammal" is"mamma.". read more