Thursday, July 18, 2013

Bloodthirsty

I agree with my colleague Lisa Lightner (she writes this paper's Outdoors column) about the hungry insects this summer. I have never been bitten so often; as I'm typing this I'm scratching several red welts on my arms and neck. The mosquitoes seem to go for my toes and ankles as soon as I swing myself up onto the hammock. It's so satisfying to swat them before they get a chance to bite! (If only international relations were so simple.)
The Cranky Friend raised an interesting science question. When a mosquito bites a human, the immediate itching sensation alerts the human to the insect's presence and allows the human to reach over and kill it. What evolutionary benefit, then, does the mosquito derive from whatever this itch-inducing chemical is? Without it, the mosquito could just fly away and live another day.

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