Baby Zombies & Villagers take damage at doors

When I have a bed inside a house in front of a door baby zombies & baby Villagers take damage on the outside while trying to get in the door. Or a baby zombie at the door starts going up and down and taking damage, same with a baby villager trying to open the door. I do not have a screenshot. Sorry.
I'm on 1.9 windows 7 pro 64 bit.
Thanks, MinerGirl98