Easy way of catching shrimps II - free shrimp trap Mark II

Hello all,
I've already showed one simple type of trap that works well with catching shrimps (RCS), scuds and snails. Here is the designs for that one.
This is another type, even easier and perhaps cheaper. It works on the same principles, and the most difficult element in building one is to find a suitable stone :-). I prefer this one at the moment because it it is better at catching snails, and should a small curious fish get trapped (guppies are great at this) it is easier to liberate it.
Picture guide:

 Any type of plastic bottle is cut into two parts. A stone is put into the bottom part. The top is inserted into the bottom, tightly. And, presto, the trap is done.

 Put a few tasty morsels into the trap and within half an hour a bunch of shrimps, snails, and scuds will have colelcted inside it.

 This is after 45 minutes - at least twenty RCS shrimp, in addition to a few snails and scuds. That means it is feeding time for the larger fish :-).

All the best,
Kasper