How can I catch someone stealing from a "public" dormitory fridge?

Question

We have a communal fridge in our dormitory where I keep several bottles of drinks (chocolate milk, juice, etc). Recently, someone has been helping themselves to my stuff without permission, and I am at my wits' end. Is there anything I can do, any creative technique for catching the person? (Short of poisoning the stuff and seeing who dies, of course. ;-)Like is there some kind of powder I could sprinkle on the bottle that would mark the perp's hands, or a relatively harmless substance, such as a laxative, that I can mix in and then observe the effects to catch the thief?

Answer 1

We have the same problem at my work, and one of my co-workers kept getting her yogurts stolen, so she mixed in dish soap with one of them,and that took care of that for a while. The someone kept stealing waterbottles so we refilled one of them with  mineral oil and resealed it, still don't know who took it.

In the end me and another guy just got one of those small dorm fridges and keep it at our desks.

Answer 2

Try the hidden camera trick.

Answer 3

Install a homing device on one of the bottles then when it disappears, track down the perp and follow it up with a cruise missile directed up their ash.  

Prepare a nice, enticing Turkey BLT and S**t sandwich for them.  

Hide your stuff in an ugly looking paper bag or something so they can't see it right off.

Answer 4

You got to do the laxative thing.. I'd vote for the 1st one.. That was awesome. My hubby and I cracked up! DO IT and then re post and tell us what happened!!!

Answer 5

You could always try this trick: put gorilla glue on the bottle/bottles. The glue is strong and it bonds on contact, so you could leave the drinks around for a while and the glue wouldn't evaporate or dry like other things, like super glue for example. So someone goes to steal your drink...and they can't put it down, literally!

I would suggest putting up some friendly notes or something before going to pranking extremes though. Some people grow up only children and don't understand personal boundaries.

Answer 6

Pshh I say lace it with laxatives. Then see who is always going to the bathroom. Good Luck. :D

Answer 7

Privatise it.