Pigs can't get in houses because they're already occupied and also can phase through walls

I had three pigs in a village that I had built unable to get in a house because the houses were already occupied. Additionally, all three of the homeless pigs could phase through fences and walls to get at the food item I had for a trap. I tried with wood fences and stone walls. We eventually had to kill them to get them to go away. 

Clip of pigs unable to get in houses: https://www.twitch.tv/knotta_gamer/clip/EnthusiasticSeductiveKleeNerfBlueBlaster-TPhQOChILwDT8Jqs