I was think about this the other night as I worked on designs for my portable critter tractor and the expansion of the rabbit colony. Motion lights work to some extent as does good fencing, especially if the fence is extended into the ground. Electric fencing is one of the better deterents but not practical for portable housing. I also set unbaited traps around the coop now and again if I know there is a predator in the area. I've found that this is hit or miss as the predators are often more intelligent than I've given then credit for in the past. Sometimes, I'll set baited traps but only a fair distance from the livestock if predator populations start to increase. I've also tried dried pepper, dog hair, urine and other scents sprinkled around the perimeter of the fence line without much success. What else have you tried or are you using to keep predators away?