Hi guys
When I first got my hive up and running I had problem with ants so I built myself some well stilts (2 pvc end caps with a slimmer pvc pipe in between, glued together with epoxy), filled them with oil, placed the hive on top and hey presto no more ants however I now have bees drowning in the oil. What can I do to deter them from the wells? I read that bees dislike peppermint oils, could I add it to the wells to stop them from going to them or will it affect the whole colony?
Hey DTM,
I had the same issue exactly. What worked for me was suspending a lid an inch or two over the top of the receptacle. This acts as a physical barrier to the bees and also keeps the rain out!
I reduced it by using a larger end cap on top. So if you have a 3" end cap as the reservoir, try a 4" for the cap. Keep the gap between the end caps around 1/4" if you can. They are hard to empty and refill that way, but you don’t need to do it very often. 
The other design I am working on is to have the end caps overlapping (but not touching). If you use a mason jar with a plastic lid as the center support, you can unscrew the jar from its lid to dismantle and change the oil.
Try replacing the oil with water, ants wont cross the water, and the water is harmless to bees.
Keep tabs on the water levels as they will drop, (the bees will drink the water) plus evaporation will also lower the levels.
After a while, it becomes obvious how quickly, or slowly the levels drop, making managing things easier.