whilst those cubys are great, to me its just another 6 or 7 £ i dont need to spend.
all you need is some sheets of wire mesh, laid flat taking up no space at all, a bit of bailer twine forming a loop tied through them all along edge and easy to carry.
i use the stuff thats only as thik as rabbit fencing but is rectangle about 1/2 in by 1 inch.
by the way secaturs( spelling) for pruning make great cutters for this wire . you can cut your slots in on the job.
find a likly set, bend your wire over the trap then just desgise it with bits of log, bark , or what ever you can find