hi,
I'm not very active on this list, as I am busy with schoolwork (im 13)
but I can suggest some places to look and traps to try as my recently
deceased gerbil (pepper) was a little escape artist. try under the bed,
behind cupboards, in the little gap underneath the last drawer in a
chest of drawers (pull the bottom drawer out and there is a little space
underneath) underneath tv/hifi cabinets and any other gaps.
To catch them, a bin on its side with food in is good, as soon as they
go in to get the food, tip the bin the right way up! or get a cardboard
tube and put food in it, and when they go in, put your hands at both
ends and they are trapped!
Thought it might help,
Charlie