Going to take the high ground and mostly ignore djb's little jab.
Food is the big thing. Anything you can do to keep food smells to a minimum. Make sure you do any dishes right after eating. Any scraps should be burned or put in the trash.
I usually bring prepackaged goods, so there's less of a chance of critters being interested.
Make sure you triple check your tent site for fire ant nests!
Hopefully you have an actual tent with tight zippers and such. Snakes in those parts are awful friendly, and will cuddle up to you for heat.