I'm going to put my 2 cents' worth here. Foot hold traps are fine, but you run a risk of catching an unintended target - your cat or dog, or a neighbor's pet for example. I'd suggest using a live trap, then killing it. That's the ONLY reason for a live trap - so if you catch your pet, you can turn it loose unharmed. NOT for relocating a predator... 
Yes, they can and they will - so you need to put up several strands of hotwire. Start out about 4" off the ground, then put one another 4-6", and so on with 4 or 5 strands. You want the first one low enough that they can't crawl under it, then the next ones close enough together to keep them from squeezing between, and the top one high enough that they can't just reach up over it and climb up.
		
		
	 
 
Good point and it registered!
I have cats that live mostly outside. I'd be crushed if I accidentally hurt them trying to protect another pet (to me chickens are also considered my pets).
My cats don't chase the chickens and, I think due to the cats' lack of aggression or stalking behavior, the chickens don't mind the cats. The chickens could care less if they have a couple of cats sitting right beside their enclosure.
On the other hand I now see the false sense of security the chickens have developed for four legged small-ish size critters.
The chickens will run, hide, flap, and flip out if they see a dog (my dogs) running toward them. But despite what some folks think about chickens and their intelligence (or lack of it) I witness my chickens knowing the difference between one dog and another.
I have 3 dogs. One will kill any chicken if given a blink of opportunity. One minds his own business. One (youngest) can sit out attached to a run cable near/within a few yards of the enclosure when I go to feed them and let them out for the day and thinks they're fun but doesn't have any desire to harm them.
 
How far from the chickens' night enclosure should the hot wire be? I mean to say, the night time fully covered area with roosts and nest/laying boxes shares walls--on 2 sides/walls--the day time pen (which is large and gives the feel of free range, is vulnerable from hawks, but contained). So, if/when I run the hot wire, I'd have to be able to turn it on/off for day/night. I assume that's easy?
So, at what distance from the actual night pen should the wire be? Close enough to zap a predator but not a wing or beak...distances?