I don't really feel guilty about killing most insects like ants or beetles or things that are really tiny like ants. However I've always preferred scooping spiders and larger bugs into a cup and tossing them outside -- though admittedly I think that's partially due to the fact that I hate the feel of squishing them and don't want to clean it up! Wasps or anything that looks like it's going to sting, however, gets eliminated as soon as possible. Mainly my policy is: if it's gonna hurt me if provoked, kill it. If it's just going to give me the creepy-crawlies and make me uncomfortable if I don't know where it went (i.e. giant black spiders!), then it gets tossed outside.