Return of the Rat

So mostly while there has been no sign of Scabbers (see here for what on earth I'm on about). There has been strange scrabbly noises and much more disturbingly I found a small pile of mini poos on the kitchen counter by the hob. Also some on the hub. I should point out that while the place isn't sterile it's not as if we leave half eaten food out or anything like that. I've moved the trap up there which is also disturbing on many levels, not least of all the fact it tries to trap my hand every time I go to use the kettle. If anyone has some (humane) rat catching tips, feel free to jump in...