I got two puppies like a week ago, The boy is a pomeranian and 4 months and the girl is a chihuahua mix and 6 weeks. However right after they both eat the male dog always tries to hump the girl. Is this normal behavior? I always separate them, but isnt he too young for that? What about her, can he hurt her badly? She sometimes lets him, but other times comes running to me for me to carry her. What should I do?