How can I keep spiders and insects out of my lights? I have a slight spider problem with my bucket light, but I don't want to get rid of them if they've already made a place to stay.

Make sure the seals are in good condition and form a tight seal between the covers and refractors. Also cable entry points is a good way for insects to get into a fitting so perhaps some silicone sealant there. Just a couple of ideas.

If your good at wood working this site http://edis.ifas.ufl.edu/uw290 has plans for a bat house, let nature take care of the insects for you and bats are very effective at controlling bugs, but yes seals in good condition also help, or you could swap out whatever type of light your running and go with a low pressure sodium light, they do attract the lowest amount of insects, but nothing is perfect in outside lighting bugs still seem to find a way in so you just clean them out every so often..