Well since this topic is in the survival forum, this might not be too gross. If you ever crushed a millipede you would know how terrible it smells. Disgusting. Funny thing that mosquitoes also think the same
Well in my
experience at least. Crush one and wipe it on your ankles => no bugs. I personally prefer to wipe it on my socks/shoes. Keeps bugs away, cats etc. away. It lasts for 45 mins. In very desperate situations wipe it on your neck. Soon your nose will ignore it..
Edited to add: not all species are suitable (I don't know which ones though), and some can cause allergic reactions.