What is best way to seal against rodents?

[HighTechRedneck]

.... cinnamon or turmeric will keep ants away

How do you apply this to keep them out?

We full time and last summer the ants were a major aggravation.  Even when we put any open foods in the fridge or glass jars, they still were a nuisance as they just kept on exploring looking for things, heaven forbid some crumbs should fall.  I tried ant bait stations inside and under underneath by the tires and flaps.  I tried boric acid, but it was virtually impossible to get it all around each tire and every time it rained it was washed away.  I poisoned nearby anthills that I found (I'll bet I killed millions of ants over the summer doing that).