This is how I made my isopod trap

Items I used to build the trap

1 * Small jam jar (cleaned and sterilized)
1 * The top cut off a 2 litre bottle (I used a Vimto bottle)
2 *  elastic bands hair bands as I could not find any elastic bands big enough!

Next I drilled a 6 mm hole into the bottle cap

Then using the elastic bands to hold the cap in place, place the bottle cap inverted into the jar, so hopefully the isopods find their way in but cannot get back out.

I bait using tetra marine crisps as they dissolve slowly an the pods really love them for some reason!!!