How to go about catching a crab?

[sawman]

i know how it feels to have unwanted crabs ...mmmmmm in my tank that is ...lol....anyway the best way i found was to use a juice bottle,with fishing line wraped around it,i put some sinkable srimp pellets in it .then droped it to the bottom,leaning up agaisnt the rocks .on a slight angle so they couldn't get out .in tottal ive caught 8 of the little buggers ..hope this works as weel for oyu as it has for me ....