My hamster is an escape artist who managed to unlock her cage and escape into the crevices of the kitchen, presumably never to be found again. If your hamster is a little hoodini as well, don't give up hope! (And once you find the little bugger, try to figure out how they escaped and make sure it doesn't happen again)
I tried making traps and finally settled on using this method. (We ended up finding her).
Basically this is a food dish that sounds an alarm when your hamster tries get to the food. The alarm didn't scare away my hamster, but instead alerted me as to where she was. Setup only takes a few minutes and most of the items can be found in your home. The alarm is very effective. I'm not responsible if this doesn't work for you, but I truly hope it does.
(By the way, this is my first instructable so constructive criticism is welcome! :) )
Materials you will need:
1. A cheap magnetic door/window alarm (I found some at the dollar store for $1 a unit. You can also get them online or at Walmart.)
2. A piece of cardboard
3. Double Stick Tape (optional) and Duct Tape
4. Hamster food (Whatever food your hamster usually eats. If you know that there is a particular kind of food they enjoy, then use that.)
5. Peanut butter. (Be careful to use only a little peanut butter. Too much is bad for your hamster.)
Step 1: Assemble the Cardboard Food Tray
Fold the cardboard in half, as demonstrated in the main image.
Step 2: Tape the Cardboard
Secure the fold with tape, as shown. Do this to both sides. The second image shows what the structure should look like after the tape.
Step 3: Fold the Top
Fold the top of the structure down as in the animation above. Do not unfold.
Step 4: Attach the Alarm System
Use double stick or duct tape to attach the thin part of the alarm to the back of the cardboard feeding tray (where you folded the top fold). The front side of the little alarm part should be facing the cardboard when attached (when you look at the back of the feeding tray, you should be seeing the back of the alarm part). Attach the remaining part of the alarm (the larger part) to the wall. Tilt the structure so that the top fold of the feeding tray is parallel to the wall, so the feeding tray is leaning against the wall and makes an upright V shape when looked at from the side. Make sure both the parts of the alarm line up correctly (as they did in the package) when you lean the alarm against the wall.
Step 5: Apply Peanut Butter and Food
Apply a small amount of peanut butter to the inside edge of the front of the feeding tray. Use the peanut butter to adhere the hamster food to the feeding tray where the peanut butter is placed. By sticking the hamster food to the inside of the feeding tray, you are making sure that your hamster has to tilt the tray down in order to access the food. This will separate the components of the alarm, causing it to go off. The finished product should be similar to the above photo. (Some of the food got knocked into the sides of the tray when my hamster knocked it away from the wall.)
Step 6: Turn the Alarm On
Turn the alarm on and wait. Good luck!