Crazy ants are in the news again, this time for expanding their range from Texas to several other states in the Southeast.

We asked our favorite ant expert, Dr. Eleanor Spicer Rice, a few questions to help us better understand what the breaking news about this invasive species really means:

What’s the big deal about crazy ants? Who are they and where did they come from?

Crazy ants are members of an ant genus called Nylanderia, and they get their name from the haphazard way they run around. When they start running, they look like they’ve lost their minds. Raspberry crazy ants (also called tawny crazy ants) come from Argentina and Brazil. They’re a big deal for three reasons. First, they aren’t from around here, which means they cause confusion for our natural habitats. Second, they build up these tremendous worker populations in their invaded area. Their huge populations help them to kick out ants that already live in the area, but, of more immediate importance to us: Third, they can live pretty much anywhere, and see no problem with moving their huge populations right on into human structures. People’s homes and workplaces are getting overrun with ants in invaded areas. They don’t sting, but it can be a big bother to have thousands of ants packed into your kitchen cabinet.

We hear crazy ants are on the move. Where are they going and why is that a problem?

Raspberry crazy ants started out around Houston, Texas, a few years ago. Since then, their populations have spread to five states and counting across the southern United States. This can be a problem for those of us who don’t like to have ants crawling around our houses all the time, and it can also be a problem for our ecosystems, which might not be prepared for an army of new ants bullying their way into the habitat.

We hear Raspberry crazy ants are pushing out fire ants. How are they doing that?

Raspberry crazy ants are probably pushing out fire ants by using their large worker populations to take the things that fire ants need for themselves, like nest space and food. They might be pushing them out through aggressive interactions, but I haven’t heard anything about that yet. It’s important to note that Raspberry crazy ants don’t sting like fire ants do.
You’ve studied a different case where one invasive species (Asian needle ant) is displacing another invasive ant (Argentine ant). How is this situation with crazy ants similar or different?

It’s similar because two invasive species are battling out for space on foreign soil. It’s also similar because, as with the Asian needle ant, the Raspberry crazy ant is pretty new to us, so we have lots of discoveries to make about these ladies, how they’re moving around our territory, and the impacts they have on the environment once they move in. Asian needle ants and Raspberry crazy ants are really different, as far as ants are concerned, and they probably use different methods to invade and establish in new environments.
We know you like to squish and sniff ants — Does this one get its name for smelling like raspberries?

I wish. Raspberry crazy ants get their name from Tom Raspberry, the observant exterminator who first realized these ants weren’t your typical Texan ants.

Thanks, Dr. E! Want to learn more about crazy ants? Be sure to check out the special preview chapter Dr. Eleanor wrote about them, part of the forthcoming NYC edition of Dr. Eleanor’s Book of Common Ants.