Nutritionally, it is said you can drink a tablespoon or two of organic apple cider vinegar and eat lots of garlic.  As well, Vitamin B1 is known to help repel bugs.

Some oils and herbs are know to work, you can look those up further for yourself.  I ran across the below recipe from TheDailyGreen.com as another option:

• 10-25 drops essential oil such as lavender, rose geranium (for ticks), coriander seeds, peppermint, cajeput and citronella
• 2 T vegetable oil
• 1 T aloe vera gel (optional)
• Combine ingredients in jar, stir to blend, dab on skin or clothing

If you want to buy one, always great to check out a product through EWG.org to see it’s safety rating.