$ 0 0 Image may be NSFW. Clik here to view. This is my favorite recipe using essential oils to keep deer flies away: 20 drops Lavender 10 drops Lemon 5 drops Eucalyptus 5 drops Tea Tree 5 drops Peppermint 3 drops Clove 2 drops Citronella Add all of these oils into an aromatherapy bottle or spray bottle and apply when going outside.