I have used bay leaves before and they work well for repelling insects. Ever noticed that on a hot summer day the cattle all tend to congregate in the shade of a big bay laurel tree? That is because there aren't as many insect type critters there to harass and irritate the cattle. Bay tree wood, known locally as pepperwood, was used as mud sill material due to the fact that it is rot and insect resistant. The stuff is real hard on the chainsaw and I have witnessed sparks appear while cutting up a huge 5 footer that was blown down in a windstorm. Up in Oregon they call it Myrtlewood.
We have entire hillsides covered with wild mint and I did not know that it was good for anything else except making a mint julip. Will try it out for insect repelling and what do you think about planting the stuff around the perimeter of my garden fence? Maybe it will keep down some of the crawling type destructive bugs.

yeah, mint has a lot of uses as a repellant. Menthol crystals are used to control tracheal mites in beehives. If you have mint local as a crop, keep an eye out for any festivals. Some of the communities in Indiana swithced over to mint when the bottom fell out of corn (many years ago). They made a good living off the mint crop. Looks like there's a bit of processing involved with mint - may be a bit ambitious for a home industry, but having it produced locally is a good resource. Also, watch for mint festivals if you have communities producing mint oil! Those are great! I personally like mint and love to try new foods.

Diatomaceous earth (DE) is another good one for critter control. It works differently than a repellent. DE is the fossilized remains of diatoms (single celled algae). To insects, DE looks like broken glass. It scratches the waxy coating all bugs have over their exoskeletons, causing them to dehydrate and dessicate. It is not as fast as chemicals, but it is also not toxic. To us it is like chalk dust. The dust can pose a breathing hazzard, like any dust, but the abbrasive effects work only on bugs. It is an old trick for preserving grain from bug infestation. We picked up a 50 lb bag of food grade DE and use it for all sorts of things - food preservation, dusting plants in the garden for aphids, japanese beatles and other pests; flea dust for pets and livestock ... lots of uses. There are two types of DE - food quality and filter quality. From what I understand the filter quality (used in high end pool and aquarium flters) is baked. This alters the nature of the DE and it is not suitable for use on food. The food grade can be consumed with the food, the amount used is negligeable and is viewed by the digestive system as calcium.

Regards,
Pat

My farming friend had a silo which, surprise, he filled with wheat. In the past, he always had problems with weevils and such. Not wanting to contaminate the food supply to solve the problem, though it was a common practice when storing wheat, he opted to try mint. There are several mint fields in Eastern Washington and the mint distilleries are usually on a portion of the field. He poured about a quart of mint all the way around the top of the inside of the silo and had no problems with infestations.

We use bay leaves or anything we can get from the mint family. Rummer has it you could even use mint chewing gum to dissuade critters. We've put mint oil, including peppermint, around tubs of herbs and things and, though the tubs are not sealed, it seemed to help.