This might seem crazy but why do I feel bad sometimes when I kill a bug?

Some people I know will laugh(thats fine, I don't care.. you are not me) but I just know there are others who feel the same. Yes for some reason I feel bad for killing little bugs.. Now I am a hunter/fishermen and I have no problem with that because its to feed my family/food(I pray over anything I eat). But, I HATE spiders.. and night crawlers alike and in the past would not hesitate to kill them. but over time, I have started to grab a paper towel put them into and let them outside far from my house, safer methods so I would avoid of having that bad feeling. But today I was careless seen a bug and I killed a Cockroach and for some reason right then I felt something like a bad feeling coming over me, grief or something (in a way I wanted to see if I felt anything, now I do regret).. I have to be honest over the past I really had no problem with but over time now that I am getting older it seems like I feel something telling me its wrong. I hope I am not the only one who feels this way about this. Thanks for answers in advance.