that works with water and sugar, I don't think that it's being drunk that's the problem, the liquid is just bait. It's probably just hard to get back to the hol

that works with water and sugar, I don't think that it's being drunk that's the problem, the liquid is just bait. It's probably just hard to get back to the hole? No space to fly, not easy to climb the inside of the bottle because of the shape (bottle top pointing down). Maybe being wet and sticky doesn't help either