They work great,I agree with the others & put upwind of you. some say that deer can smell them but I think the 1 deer that smells it is nothing to all the deer that will bust you because you are moving around swatting bugs. use it and u will notice when the butane cartridge runs out because the bugs attack. you can buy spare butane cartridges in the beauty dept. of large stores Connair sells them for butane powered curling irons. Mine stopped working after 4 years of long use. They have great cust service & rerpaired it at no cost. I also bought a spare so i'm never without.