I got this trap to catch and relocate squirrels that have been getting somewhere in the roof area of my house (unsure exactly where but I could hear them from inside my house). I have a two story house and saw how they were getting in -- by running fast along the top of a wooden fence to gain momentum then quickly running along the side of the house (like they were Spider-man) to reach a low-point of the roof. I checked all along the house and this was the only way that they could reach the roof due to the height. So I set the trap up on top of the fence near the house (secured it to the fence so it would not fall). First day I caught a squirrel. I set the trap up again the next day and caught another squirrel. I set the trap up again the next day and caught a possum (I didn't know possums could climb)! Three attempts -- three catches! I stopped using the trap with the possum catch. I don't know how many squirrels were on my roof but I no longer hear any noises up there so I think I got them all.
Bait used was bird feed. I put it in a plastic cap from a hairspray can as it was small enough to fit on the other side of the panel that sets the trap without hindering movement of the mechanism.
One thing to be prepared for (for those that have concern) is that a trapped animal will try to get out, and with a metal trap they may injure themselves. Each of the three animals caught had some sort of injury and were bleeding -- not life threatening but there were some minor cuts. The possum was so large he barely fit in the trap and actually got stuck as he tried to bite his way out and his lower jaw got stuck in an opening between the cage wires. We had to help him get unstuck. If you are uncomfortable doing this sort of thing, you might want to first find a friend who isn't or have a service remove the animals for you. If you want to minimize injury to the animals, make sure you monitor the trap frequently so that the animal isn't caught in the trap all day which would increase the likelihood that they will injure themselves.