By their very definition, mammals make milk. It’s one of the three things that make mammals who they are. So we shouldn’t be surprised that the very word “mammal” reflects that. The word originally comes from the Latin word mammalis, which means “of the breast”. That word comes from original root “mama” meaning breast. Naturally, the word “mama” also means mother, and nearly every indo-European language has a similar sounding-term for mother. One theory holds that “mama” is the sound that a baby makes after sucking on a breast, and the sound developed the same meaning across languages organically.
– A few thoughts from your friend Saxo