I figured out an awesome way to trap ants. I guess its only really useful if you want to collect them dead though.
1) Have a party
2) Leave a glass with about 4-5 cm of some unidentifiable sugary-alcohol-type mixture in the bottom of it somewhere where you won’t see it
3) Wait 2 weeks
4) Follow the line of ants to the glass
5) You will see a layer of about 3-5 cm of dead ants, with more ants plunging into it lemming-style.
From there, you can do what you will with your new pile of dead ants. By the way, dead ants don’t flush all that well.