Feral cats and stray cats roaming your property can be a problem. They reproduce and can carry disease. You can capture feral and stray cats in a humane manner with a simple drop trap and take them to your local Humane Society or Animal Control. These organizations can evaluate the condition of the animal, address any health issues, and possibly find a home for the cat.
Determine the base size of your cat trap. The necessary size varies according to the size of the cat you want to capture. Make sure you allow plenty of room to allow for the cat's tail. A typical good size is 3 feet wide by 2 feet deep.
Cut eight pieces of 1-by-1 inch wood (or any other lightweight framing wood) for the base frame and the top frame of the cat trap. For a 3' x 2' trap, cut four 3-foot pieces and four 2-foot pieces.
Construct the base and top frames by securing the cut frame pieces with nails.
Cut four pieces of wood to serve as the corner pieces. These pieces connect the base and top frames. Pieces about 1 foot in length should be sufficient. For larger cats, increase this length to prevent harming the cat.
Secure each corner piece to base frame with nails, then secure the top frame in the same manner.
Build a sliding door on one of the sides of the trap by cutting a piece of plywood, and then creating sliding rails on either side with 1-by-1 inch wood or other scrap wood. When you have trapped a cat, you can place a cat carrier at the door, lift the piece of plywood, and transfer the cat from the trap to the carrier.
Stretch nylon netting across the top and sides of the trap frame. Cut the netting to fit and secure the netting with nails. Do not cover the door area or the bottom of the trap with netting.
Cut a 1-foot piece of 1-by-1 inch piece of wood to prop the trap. Tie a long piece of string to the wood. This allows you to sit at a distance and pull the string to lower the trap when the cat is under the propped trap.
Place a bowl of food under the propped trap to attract the cat.