bug repellant made with 1 liter of vodka (cheapest you cab find) soak whole cloves (24-30) overnight in vodka. Strain out cloves, put clove-infused vodka in spray bottle, add 1 tbsp of vegetable oil and shake up. Oil helps it stick - can spray on dog and also humans. Also works outside as bug repellant. I have also heard that brewer's yeast works as a flea repellant. It is best ingested but dogs having acute sense of smell may balk if something is different in the food bowl. Cats clean themselves so it's easier to get them to ingest by putting on fur.