Why do animals have nipples?

For female animals, it is to feed their children (like human babies). For males, however, it is believed that it is because in the womb every animals starts off as a female (The same as human babies) and once given male parts the nipples don't really leave. (Sorry if this doesn't make sense)

Many male mammals, humans included, have nipples. Scientists believe that the reason behind this is the result of natural genetic selection - - or lack thereof. Male and female animals start out life almost identical in utero, complete with nipples.