i have caught a few rats this way over the allotments,when they try to go from one shed to another,i just put a piece of netting in between the sheds because they had to run about 6 or 8 feet to get to the other shed,then either smoke them out or ferret them just to get them moving, the netting i used to use was green micro mesh sheet netting from the garden centre and prop it up on sticks and peg the bottom down leave plenty of bagging near the floor level, good bit of fun, all the best, jay.