is it unethical to kill bugs?

[Diana]

I've seen a fly and a ladybug climb up a glass window, so I don't know about putting jars around bed legs to keep bugs out.

It works with spiders and all insects I've ever had in my house. In Arizona that is one of the techniques to keep scorpions away from a bed. The insects just slide trying to crawl out of a glass. However, in the case of a ladybug I would just take it outside by hand   and flies can be let out the window. The reason flies are on the window in the first place is because they want to be outside.