Making a cheap snail trap

I decide to make myself a cheap snail trap for my Aquarium.

I popped down to a local B&Q store (I'm in the UK) and bought a bag of
4 plastic Settee caster covers for £2.20 and a zinc plated 6mm wide, 3
inch long screw (25p) and some nuts (50p).

I then drilled a series of small 2mm holes around the rim of two of the
covers and a 6mm hole in the centre.

I then placed the screw through both covers so that they act like a
shell.
The advantage of the screw and nuts is that I can easily adjust the gap
between the two halves so that I can only catch small snails if I want
and it sinks quickly.
Finally I tie a long piece of cotton thread to the screw.


The result is a wee 'cave' that the snails love to go into as it's nice
and dark and I place a small piece of Spinach in it and leave it in the
aquarium overnight.
In the morning I've usually got 20 or so wee snails and I just pull on
the cotton thread to remove it without getting my hands wet.

Total cost : < £3.00
Commerical snail traps are usually around £7!

It works very well!