[David]

Why not just try and capture some ants? I think all our houses have them. I especially like those small red ants. All I need to do is to take a cloth, wet it, open it up and throw it on top of the ants. They'll be stuck on the cloth fr a while. Then I use tweezers to slowly pick them up and feed them to my Sundews.

The other way is just to collect them outside my apartment at night under ceiling lights. Just carry a bottle with cap, pick them and throw them into the bottle.