Mosquito bites are caused by the female mosquito. They pierce the skin to suck your blood and deposit a protein-rich saliva that keeps it from clotting. Your immune system reacts to the foreign proteins, resulting in itching and redness. Those bitches.

The amount REI has donated to local outdoor recreation clubs since 1976.

Jungle Juice

Leave it to a brand that's been outfitting outdoor types for seven decades to come up with the best way to keep bugs at bay. REI developed Jungle Juice with bug spray maker Sawyer as a maximum-strength repellent that has proven effective against mosquitoes, gnats and ticks (among others) for up to 10 hours. Plus, the handsome 2.5 ounce squirt bottle is a lot more travel friendly than a bulky aerosol that just ends up misting everything else around you. But remember that this stuff is the real deal, meaning a little goes a long way. You only need four to six drops per application.

$7, at REI