What should you do when a cat is living under your porch?

I hav two of my own cats, but hav often had to deal with stray cats and homeless animals. Try to tempt it out ... show it you are a friend. Giv it some semi-skimmed milk or tuna .. maybe the milk first because it could be dehydrated, and milk is bad for cat's digestion, so food would be best later. leave the food out, then when you can, leave some ina cat basket, then try to catch it and take it to your local animal shelter. Good luck!