Call the SPCA or a no kill shelter, like Cat Angel Network.

Trapping & relocating is cruel not only to the cats, but to others that would have to deal with the problem. The poor things are probably starving & didn't ask to be born with no where to get a meal. Imagine if you were homeless & starving, you'd want someone to help you. Don't get me wrong, I understand it's a problem that's out of control, but do the right thing.

In our neighborood, we got some fixed, found homes for others & had the CAN come to get the rest where they found good homes! Solved the problem, no more stray population..........all done humanely.