Health

Ballpark Bugs ' Flying Ants

By CBSNews.com staff CBSNews.com staff

January 31, 2002 / 8:40 AM EST / CBS

A swarm of flying ants upstaged the Detroit Tigers and the Seattle Mariners game at Comerica Park in Michigan on Wednesday. As it turned out, these ants are harmless and are merely trying to mate.

Our guest, Michigan State University entomologist Howard Russell explains to us that Wednesday's swarm of ants was only an annoyance.

The most remarkable thing about the ants that swarmed Wednesday night was their sheer numbers. My experience with people and their interaction with insects is that people just don't like bugs, but they can tolerate them when there's just one or two of them on occasion. When people come across an incredible display of numbers like this, they get nervous. But, people should remember, these ants are harmless, they're not interested in biting, not interested in feeding, they're just interested in mating. They're just a garden variety of field ants, and you've probably got them in your backyard.

It was really a coincidence that they swarmed over Comerica Park. There has been some suggestion that the colonies are actually under the park, but that's probably not right. The grass has only been there since November. Since Comerica is so new, it's reasonable to think that whatever colonies were there were destroyed during construction. Could colonies that were there reform and get large enough to produce this number of winged adults in that short time? I doubt it. A better theory is that Comerica's sheer size could have attracted these ants. Mating swarms always occur at a hilltop or a feature, a geological feature. Comerica's a really large, really new geological feature.

What Can People Do When These Swarms Come to Town?

Grin and bear it. Leave the area. There really isn't a repellent for these things. In terms of the fire that the players lit, I don't think it did anything. It was just a primal reaction. You see something you don't like, wave a fire at it. I think it was more a hope and a prayer that it would work. These things are only going to land on you momentarily on their way to somewhere else. So, I don't know, wear loose fitting clothes, the worse thing that could happen is that you inhale some. In terms of bug sprays and poisons, I'm not an advocate of the indiscriminate use of insecticide. It's not an effective control, it's really more of a recreational activity or revenge.

It's actually a good thing that so many ants from so many different colonies came out at once, maybe 10,000 of these "swarmers." They're short-lived, so they come out to mix and mate with different colonies. Much like you wouldn't mate with your brother or sister, it's genetically beneficial for the ants to mate with other colonies, it makes the species more robust. Also, there are many animals that feed on flying insects, it helps to have strength in numbers when you mate, because the predators an only eat so much before they have to stop. In terms of why so many showed up all at once, they are known to key-in on the difference between the length of day to night, there's an association with recent rainfall, the phase of the moon. Who knows? Science is not that advanced yet.

People should remember that these are beneficial insects. If you leave them alone and let them mate, they're going to limit the other creepy-crawlies that are out there.