We have a few rats in the garden and have bought a Monarch Live Capture Rat
Trap.
It is the second one down on this page:
http://www.trapman.co.uk/rat-traps.htm

It is not working too well. The rats dive in and out of the right-hand side
and only a couple of medium sized rats have been heavy enough to lower the
flap in the middle.

I have been trying to devise a way of putting a trap door at the entry point
on the right-hand side or fixing something on that I could yank remotely to
keep the little blighters in the trap.

Anyone got any suggestions to adapt this trap please? (No poison
suggestions please as we have a lot of wildlife)