This is why I keep my pigs and wolves in armored pens. Thats a an enclosure with raised-earth walls and a full roof, with a second un-roofed earth wall at least 4m away from the pens surrounding all the pens. The outter wall keeps most things out of striking distance of the animals in the pens, and the actual pens keep bats out, keeps blobs far enough away that they cant poison anything inside, and protects the animals from drake attacks.