TriSana Nutrition Garlic is a popular supplement to be given to ward off flies and mosquitos. It is said to leave an unfavorable smell to these bugs once the garlic has been digested and absorbed.  Garlic has also been studied worldwide and shown to have a positive protective effect on the heart and the kidneys, in part due to the selenium and sulfur present.
It is important that you follow feeding guidelines to maintain the safety levels of this supplement.