Thought this was interesting....I have used eucalyptus but never peppermint oil in an effort to deter flies. I have tended to keep old bits of log/wood to absorb the oil then put near the bunnies cages but not tooo near, seems to work well. Thought others might be interested in this and this is the company I used to by Harriet's essiac tea from, they are very helpful and really nice people.