If you think they may become victim to ants, there are two ways to prevent this : a barrier of vasaline works to prevent ants from crossing ( very messy though ) or just put each vial in a dish of 1/2 inch of water. The water will also help hydrate the vial.
I have carpenter ants here and they have attacked a couple of my slings. I take as many non-toxic approaches as possible to avert them.. dryer sheets wiped down on my shelves, my sling vivs sitting IN water dishes, Sol U Mel... a Melaleuca product, and plain ol' squishing on sight.
Fortunately, I have not lost anyone... but they will go after leftover bug parts and the moisture, for sure... as already mentioned.
generally we try to keep our tanks as clean as we can, removing body parts and poop almost daily. but of course, its impossible to make things ant proof so in the past i've distracted their attention else where to keep them away from the tanks with homemade ant traps...just vials with sugar water and a little dishsoap that has small holes poked in the top, once they get in they usually drown or cant get out and drown later on. i do that long enough to distract them and then wipe away the sugar trail they leave behind going to the tanks with a little bleach and a lot of hot water, and then they cant find their way back to the animals for months.