I had an unwanted Damsel in my tank.I didn't feel like taking apart my rockwork and was about to buy a fishtrap.I found out you could just simply make one out of a water bottle.
You get an empty water bottle and cut the top off.You invert the top and poke holes on the sides and twist tie the top.You will want twist ties because you'll have to open it back up to get the pest out.
You don't feed your tank for a couple of days and drop the trap in with food in it.
After one hour I caught a pepermint shrimp and an hour after that I caught the damsel.

You get an empty water bottle and cut the top off.You invert the top and poke holes on the sides and twist tie the top.You will want twist ties because you'll have to open it back up to get the pest out.

After one hour I caught a pepermint shrimp and an hour after that I caught the damsel.