Mosquitos

No citronella candles, no bug zappers, no DEET, nothing expensive or high-tech? Try a fan, as mosquitos are weak fliers and can usually not withstand the onslaught of even the slightest breeze.

Of course, most of the world, where mosquitos wreak greater havoc, do not have reliable electric grids. So fans may not be an answer for them. On the other hand, maybe your generosity is. Click here to see how you might help.