I the mammal is a monotreme, it developes in an egg. If the mammal is in the marsupial group, it develops in a pouch on its mother. If it is a placental mammal, it develops in the placenta.
The fetus develops in the womb of the mother.
All young mammals develop in the amniotic sac of their mother. For example, a human fetus develops in the mother's womb. Which is an anmiotic sac.
In a way, you could say "both inside and outside". The egg is produced and fertilized inside the mother. She lays the egg and incubates it so the embryo grows outside the mother and develops into the hatchling hummingbird.
uterus
a mammal feeds his young with milk from the mother and has hair
A placental mammal retains the young inside the body of the female and are born alive.
Mother mammals make milk for their offspring.
In mammals, the embryo develops with in the specialised part of the oviduct .
no your mother is
A developing mammal inside of the mother.
Insects start as eggs and mammal's are born from there mother