A Reuters report from London:

They're small, but mighty.

Termite flatulence is to blame for as much as one-fifth of the world's methane, one of the "greenhouse gases" causing global warming, scientists said Thursday.

The termites produce about 88 million tons of methane a year as they munch their way through decayed trees and other forest soil, Paul Eggleton of Britain's Natural Environment Research Council said.

"It's a lot of methane but there are a lot of termites," Eggleton said in a telephone interview. There are more than 3,000 species of termite in the tropics.

Eggleton said it was not the termites that destroy houses that were to blame. "It's the ones that actually feed in the soil that produce methane," he said.

Eggleton, a termite biologist, and colleagues were taking part in a five-year project to find out how many termites there are and how much methane they produce.

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