This is the 3rd colony that has done this to the Terro bait that I've put down. The first two colonies in a different area have seemed to disappear after a few weeks despite doing this to the bait and not seemingly taking much of it back. They covered the circle entirely with sand and there was very little activity. In this picture you could see they are starting to do the same thing but on the back side you can see a bunch of them still munching from it - they are staying stationary for long periods of time. Do they do this to keep it from evaporating or have they identified this is poison and keeping others away from it?