The next lot of banana disappeared, so I grabbed
major_clanger's screwdriver and swung into action. Well, flopped on my tummy on the floor to investigate the cupboard construction. Not an entirely simple job, I list the steps here so that I can do them in reverse in the morning:
1) Loosen screws holding cupboard door; wiggle door and remove from cupboard.
2) Two small screws are now accessible. Remove them.
3) Remove vertical piece of facing wood.
4) You can now access the large screw holding the bottom facing on. Remove screw, remove wood.
5) And
now you can access the large screw holding the bottom facing for the adjacent cupboard. Remove screw, remove wood.
6) Peer underneath.
7) See hamster's little snuffly nose! He has made himself a nice nest out of a J-cloth, and made a little heap of banana!!
8) Quickly block water pipe exit with a handy towel to prevent hamster escaping down it.
9) Fetch flatmate to look at cute hamster nest.
10) Consider fetching camera to photograph cute hamster nest, but then hamster emerges.
11) Block his retreat with bits of removed wood, failing in your excitement to remember which one came from where.
12) Eventually he is out in the room, with no hidey-hole to go to. He stands behind the step-ladder and thinks "This is a good hiding place!" It is not. Imagine an elephant hiding behind a tree, and scale down to hamster-size.
13) Catch him and put him back securely in his tank.
14) Dance around chanting "We're better than yoo-oou, we're better than yoo-oou!"
15) Go To Bed.