Outside and at the campsite is where the Ant Barrier really shines!! You can put it right in the middle of an ant trail, or on an ant mound and have no problems. As long as you have some type of deterrent in the moat - dishwashing liquid, cooking oil, petroleum jelly, water, etc, its impossible for small crawling insects to reach the Food Holder. You can leave it outside for days, weeks, even months without having to worry.
Q: Is it allright to use the Ant Barrier outside?
Longevity depends on the product that you install in the moat. If you fill with water, you have to monitor evaporation. The contents of the moat is always shaded from direct sun by the Food Holder so water would last for quite some time.
If you put Cooking oil or Biodegradable Lubricants in it, you can come back next year and the Ant Barrier would still be hard at work deterring ants.