Can't help with bedbugs, but keeping ants out and off can be easily down by spreading baby powder where you do not want them. They will not cross it, or if they do, they can't stand it and leave. It works, I've tried it.

Here are a couple of things I found online re' bed bugs:

A mixture of salt and boric acid may help you to get rid of bugs. From http://pests.in

and

one time i was in a hostel on oahu and the bedbugs were bad. we took a ton of baking soda and rubbed it onto the bare mattress, in the crevices and left a layer of it there and then put the sheet on and it helped them stay away, i heard it's because they suffocate.

Some helpful stuff .