You could use talpex traps, dig them in and then cover to disguise as a molehill, the benefit with these little traps is they work well and the covering over wont imepede the powerfull spring.
I would however only put a couple in at a time, you know the saying " all eggs and basket etc etc", because at around six and a half quid a pop if you cant find them cheaper, could soon cause teary eyes!!