Apr 8, 2011 – Just Don’t Anger Them

QUESTION:

Is the California Harvester ant a docile, retiring sort of ant?

ANSWER:

I would say that Harvester Ants in general - black and red and including the huge kinds found in the Southwest - are inclined to mind their own business until you mess with them. They feed almost exclusively on seeds, and only very rarely enter structures since their food resources are not normally found there. However, they are 2-node ants equipped with a very capable stinger, and if they were angry enough at a person they will inflict a very painful sting. This could happen if someone stood on their nest opening or got some of them trapped in clothing, in which case they will defend themselves or their colony. They are large and fast moving, and definitely will cause some pain.

For this reason I would not characterize them as docile, but only that they keep to themselves if possible. But, it is very common for these ants to nest around structures and in landscape, where encounters with people or pets would be very likely to happen. If it happened to be a child care facility or school, I believe it would be inappropriate to leave these ants there, and killing them in the name of child safety would be proper. Since their food preference is pretty restricted to natural materials they are not as likely to accept baits as are scavenger ants, but you still could try granular bait products. Otherwise, directly treating into the nest opening with a dust or some other formulation would be effective. They often are active during the daytime, and red harvester ants in particular have very obvious nest openings, with large, circular areas around the opening as they bring out soil and dump it at the outer ring.