Snapping turtles are an interesting species of turtle. While most turtles will bite if they're cornered or threatened, snapping turtles will most certainly cause immense pain and bodily injury when they bite; even the small ones will take a chunk out of someone's finger. Therefore, it is a good idea to remove them from your pond or stream to keep you, your young children and your pets safe. An easy way to do this is by trapping and relocating them. You can build your own trap at home.
Make a top, bottom and two-sided crate out of the four large BBQ grates. BBQ grates are useful because they are sturdy, made of metal and readily available. Connect them together with ample wire so that the cage remains intact even if there's a large snapping turtle inside.
Use one of the smaller grates to create the back end of the trap. It doesn't have to be exactly the right size, but make sure it is secured tightly with wire to hold a snapping turtle.
Place the second smaller grate over the opening of the crate. This one needs to be smaller than the opening to allow the turtle to get in. Make sure it's not too much smaller, though, as you don't want the turtle to get out once it's inside. Place the grate at an angle so that the top of the grate meets the top of the crate's opening, and the bottom of the grate is set a few inches inside the crate's opening at the bottom.
Secure the top of the small grate to the crate with wire. Create makeshift hinges. Make sure that you can push the grate open toward the inside of the cage (much like a doggie-door) but that you can't swing it outward. The grate should stick to the bottom of the cage, unable to open outwardly, which is what you want.
Place your two springs on both sides of the small grate. Connect them with wire, and then also connect them to the sides of the crate you've made. This will help close the newly made door quicker, trapping your turtle inside.
Attach the two-liter plastic bottles to the outside of the cage with wire, rope or string. The bottles should be about halfway down the cage, two on either side of the trap, ensuring that the trap floats once the turtle is inside. Turtles need air, too, so the trap needs to be able to hold a 10-pound turtle and the cage; add more bottles if necessary.
Place a small fish tied to a string as bait inside the cage, and place the trap in an area where you have seen snapping turtles before (often in shallow water, near fallen logs or branches). Attach the trap to the branches with rope so it doesn't float away, and wait overnight to see if you've caught anything.