Insect bites :/

well today when walking my lovely dogs, Maddie and Sparky, i managed to get bitten through my leggings resulting in a large lump, like it had swelled :/ i think i could be an allergic reaction i hope not as i don't know what bit me... so from now i have decided i HATE insects... they are only around to make life a difficult. do they really have nothing better to do than to eat me??? honestly its ridiculous.