We stayed at a lovely place in Costa Rica - new construction, air conditioned, clean. We were on a budget and did a little cooking, and when I say we were on a budget and did a little cooking I mean we bought a hunk of cheese, some tortillas, and a bag of pancake mix and that is what we ate for a week. We found as soon as we opened the tortillas and started making quesadillas, the ants were instant. If you sat down to eat, and left the table for a few minutes, ants were all over looking for the yumminess. We never assigned blame to the condo, but rather the environment. As there was a refrigerator, we simply kept everything in the refrigerator - nothing in the cupboards, washed dishes immediately, etc.
If you think it could be a matter where people just aren't used to the tropical environment, maybe just leave some information on storing food/cleaning up immediately?
Maybe in the review you could mention that it is a tropical environment and like most homes in tropical environments there will be insects from time to time, but this should not be a problem if you keep food stored tightly in containers and don't leave out dirty dishes?
