Interestingly enough, I used some bait in my room the other week and I had heaps of ant boats in my tanks. most still alive. Reminded me of what you hear about in the concentration camps with the strongest ant being at the top not drowning. Anyway, I assumed it was because the poison drys them out and makes them seek out water. My fish were snacking away on them and thus far, no issues with the fish. So I wondered if because they were always in the water if it somehow nullified it to a degree.