Most female mammals have nipples. The platypus is one exception (they have pores).
Nipples will darken during pregnancy.
When I was pregnant with my son my nipples got darker.
The same way you make a guy's nipples hard.
No the nipples do not change colors.
The nipples get larger so as to better suckle the baby.
no thay are fish Only mammals have nipples
All mammals have nipples, even male mammals-thoughs bumps are nipples.
Only mammals have nipples, and are for suckling their young.
Thorny devils are not mammals: they do not have nipples.
Yes, all mammals have nipples (aka teats).
Male rats don't have nipples.
No they do not, nipples are not needed. Nipples are a feature of mammals, which suckle their young. Cockroaches are insects and do not suckle their young so they do not have nipples.
No. Tarantulas are not mammals they are arachnids
Lobsters are arthropods. Only mammals (and not all of those) have nipples.
No. Frogs are amphibians not mammals. This means they do not nurse their young and have no need for nipples.
No, They all do not have nipples and all live on land, dolphins live in the sea and are mammals, secondly they do not all have nipples either, case in point, monotremes, like the platypus where even the females dont have nipples.
Yes. All mammals of both sexes (except for monotremes) have nipples.