The box said it was ant proof which I liked because I am currently in the middle of a turf war with a bunch thug carpenter ants. I read the instructions, I fil it up and hang it in a tree where I hope hummingbirds can find it.
A couple days later I go and check on it, and there are no ants inside but a bunch of dead earwigs. (Side note - I hate earwigs - so gross looking. What is their purpose in the food chain? Who eats them??? )
Any hoodles - so today I had some time to kill while I waited for train that was blocking the road and popped into a Birding store. I tell the lady that I had this ant-free hummingbird feeder and that it has earwigs in it. She asks me if I fill up the centre moat compartment with water. Um-no. - "Well there's your problem" (a la Adam Savage of Mythbusters)
*(not my photo)