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Posted at 11:00 AM ET, 02/05/2009

Warm Weather: When the Ants Come Marching In

Wx and the City

* Warming Up? Full Forecast | Backlash Against AccuWeather Hype *

Temperatures well above average are on their way for this weekend, according to our latest forecast. During a warm spell in late December, Capital Weather Gang commenter Bobosnow noted:

Ants!!! This happened around Thanksgiving or early Dec as well with rain accompanied by a freak warm-up. Hate it. Never had them before, but since I removed my front tree in May, have had these 2 incidents. I know it's weather-related, used to happen at my mom's house all the time - a quick warm up or rapid weather change, usually with rain, and they come in the house.

Apparently, winter ant invasions are a common occurrence. This leaves me wondering: What kind of winter weather is most likely to force ants out of hibernation? And how important is the weather in triggering an ant invasion compared to, say, a kitchen full of crumbs? -- a veritable ant feast.

Keep reading for more on how the weather affects ants...

Unlike mammals, ants are cold-blooded -- their body temperature fluctuates along with the surrounding temperature instead of staying constant. Thus, their metabolism slows down during cold winters and they cannot function at all below certain temperatures -- usually lower than 50 degrees Fahrenheit.

If ants get wet and are exposed to freezing temperatures, they're toast. So, they find strategies to stay warm and dry, like going through diapause (a state similar to hibernation) in deep underground tunnels. They don't usually eat much, if anything, during winter.

Have ants or other pests invaded your house this winter, and have you noticed a correlation to certain types of weather?

One type of ant that can occasionally be seen indoors during winter is the carpenter ant. Carpenter ants spend winter laying dormant in underground colonies. If the soil where they are hibernating heats up (pdf) from warm temperatures, some of the ants may become active and wander indoors. But, if soil temperatures get too cold and they are nearby a building, they may come indoors to find warmth.

If you do see carpenter ants in your home in winter, a likely possibility is that they're nesting in your walls or under the floor of your house. Since carpenter ants actually chew tunnels in your walls, I hope your invaders are a less worrisome species, such as the odorous house ant. Here's how to tell the difference.

This leaves me again to wonder: If warm temperatures last for several days, and ants are attracted to sweets...will the invaders return for Valentine's Day?

By  |  11:00 AM ET, 02/05/2009

Categories:  Nature, Nature, Nature

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