Rat traps are alright but are prone to breakage or loss as in your case. I'd recommend you aquire some #0 longspring traps. They are dynamite on rats, will last forever and have the proper chain and rings to securely stake them down. They will also hold a small possum or coon for at least a little while. If you are targeting larger animals, use a # 1 1/2 sleepy creek longspring. They are my go-to coon, mink and muskrat trap for fur trapping and will hold even the biggest coons if checked regularly. They also have the benefit of being able to release dogs or cats relatively unharmed. The lock time is too slow to get most raptors. A good source for both is Minnesota trapline products or Funke trap tags and supplies.