Passive Mobs going through walls

[Aussiekillerrat]

Im having trouble creating farms like chicken farms when they keep pushing each other through walls is there any way to fix this? 

[JaariAtmc]

Nope, that's a vanilla bug that's like finally (hopefully) fixed in Minecraft 1.9.

You could try placing conveyor blocks around the farm, which push the chickens back to the middle.

[Aussiekillerrat]

thanks