Oh wow. I had a similar rat-thing under my house. I called it a monster and everyone laughed when I said I was going to catch that thing. I caught it alright. The darn thing would come out on the back porch where I was growing my tomatoes and cut the plants down. I used a head of lettuce and a live trap like you have and caught her. YUCK. I drove her away and let her go and so far - she hasn't returned. Glad you caught yours!