Washington D.C.'s Division of Public Works has found a way to stop rats cold – VERY cold – using non-toxic dry ice.
The nation's capital has always had a problem with rats... and we don't mean your garden-variety congress critters, either. Nope, we're talking rodents: fur-bearin', disease-spreadin', disgust-inducin' varmints that have plagued (pun intended) mankind from the dawn of civilization.
Many types of potent poisons have been used to control rat populations but they have many drawbacks, chief of which is inter-species toxicity. With poisons having fallen out of favor, other solutions are being investigated. One of the most promising appears to be frozen carbon dioxide, better known as Dry Ice. Washington D.C.'s Division of Public Works is currently testing dry ice as a form of rat control and early results have been very encouraging.
Dry ice doesn't melt – it sublimates directly into carbon dioxide gas. When dry ice pellets are deposited into rat burrows, the heavier-than-air gas sinks to the lower levels of the burrow where rats nest and congregate. The rats painlessly suffocate and there's no toxic residue left behind to contaminate soil or ground water.
“This has been tried in cities around the country,” according to Tommy Wells, Director of the Department of Energy & Environment. “Currently the E.P.A. says a person can do this on their own property - you're not prevented from doing that.” Normal pest control precautions still apply, however, as you want the rats to chill out and not you or your family. (via DCW50 and WUSA-9)