Going to straighten a few beliefs out-- muskrat and beaver--do not chew off their feet. They spin and twist when caught--thus the word--wring off-the stoploss or guard trap, keeps rats legs and feet from twisting,thus they stay in the trap where they belong.
By the way--I redesigned that trap for the Duke company, 4 or 5 years ago.
Thats my main muskrat trap.
My puter actually stayed on for a bit.
Tom