Well, there are two possibilities. 1, the male does not know that she is pregnant. He probably cannot tell the difference. Then there is possibility #2. Possibility #2 is that the male is younger, and simply wants to play. If the female starts growling, please understand the reason. She is probably scared about her babies. Anyway, if the male is younger, #2 is probably correct. If he is older or her age, #1 is probably correct. If the male gets physical and aggressive, take him to a vet or a place like petco. Hope this helps!