Here at home on our farm in southeastern Maine, we have a horrible mosquito problem, they’re the size of small Cessnas and incredibly bloodthirsty and tenacious…
and that’s not even counting the other bloodthirsty parasites we have to deal with, Black Flies, Deerflies, Horseflies/Greenheads, Mooseflies, Stable flies, and ticks (both Wood, and Deer ticks)
if you have one micron of unprotected skin exposed, they will find it…
Needless to say, i’ve tried a lot of bug repellents, here’s how they stack up
Ignoring the mosquitoes; completely innefective, as you are swarmed seconds after setting foot outside, effectiveness rating, 0 out of 10
Swatting the mosquitoes; while it does give the satisfaction of killing the little smeggers, it’s equally ineffective as Ignoring (0 out of 10)
10-30% Deet repellents; Off, Cutter, Deep Woods Off, etc… poor effectiveness, anything below 15% deet is totally useless, Deep Woods Off only lasts for about 15 minutes before you need to re-apply, regular Off and Cutter sprays are laughed at, rating; 2 out of 10
“Natural” repellents; citronella sprays, Naturapel Plus, Avon Skin So Soft… Poor effectiveness, right down there with the 10-30% Deet sprays, Naturapel Plus lasts only 20 minutes before reapplication is neccecary, the only advantage of the natural repellents is that you’re not hosing yourself down with the noxious chemical known as Deet
Ben’s 100 (100% Deet); Ahh, here we go, the Heavy Artillery of bug spray, Ben’s just works, slather on the Ben’s 100 and you’re mosquito/deerfly/horsefly/tick free for a good long time, easily all day, Ben’s is the only stuff that works on our mosquitoes, however, at 100% deet (well, actually 98.11% deet, but who’s counting?.. 
), it’s very strong, and must be used sparingly, it’s too strong for kids under 10, and probably not too good for adults either, however, i’ve been using the stuff since high school and haven’t died yet, nor have i grown a third arm or gained any mutant powers, so i’d guess it’s “safe” enough…
Ben’s 100 is the benchmark, the standard by which i judge other bug sprays, Ben’s gets a 10 out of 10 rating, that little blaze orange bottle is great stuff…
Thermacell Mosquito Repellent Device; i was skeptical, i’ve tried all sorts of gimmicky mosquito repelling devices, and none of them worked, the worst one was a little AA battery powered Ultrasonic mosquito repeller that actually ATTRACTED more mosquitoes than just going unprotected, needless to say, i didn’t have much confidence in the Thermacell unit, i was fully expecting it to be another useless, gimmicky device
the Thermacell uses a butane cartridge to create a flame that heats a metal plate, on top of this plate is placed a Thermacell Mat, a small pad containing D-cis/trans allerthin, a Geranium based compound, the pad is heated by the plate, and releases the allerthin into the air, where it creates a 10-15 foot “safe zone” that mosquitoes and other biting insects avoid, in theory, at least
the Thermacell unit does have a few drawbacks, the protection zone is only really effective in still air, wind will disperse the repellent, and the portable unit must be laid down flat on a flat surface, and must have all it’s vents unobstructed, as it generates heat, you can’t place it near any combustable items, and it’s not reccomended to use it in close proximity to food, best to put it on the ground, like a citronella candle, it also takes about 10-15 minutes for it to establish a “safe zone”
that said, the big question is "Will it work on our vicious mosquitoes?
Actually, it does, and it works rather well, in fact, this morning i was fishing in our pond, sitting on our raft/dock, and there were no mosquitoes bothering me, in fact, i noticed a horsefly sitting on the edge of the dock, in what could best be described as a “stupor”, it made no attempts to bite me, and our horsefly problem is worse than our mosquito problem, tonight, i tried it again at dinner, sitting outside on our patio, the Thermacell unit sitting on a brick tile on the ground, once again we were mosquito-free, for the most part, occasionally we’d get a straggler flying in, or carried in on a gust of wind, but they didn’t stay around to try and bite, they left the “safe zone” rather quickly in fact
the Thermacell repeller actually works, and it’s almost as effective as Ben’s 100, i’d rate the Thermacell device as an 8.5 out of 10