Adams Pet Spray products come in both alcohol and water-based formulas. Some contain adulticides only, while others contain both an adulticide and the Infest Stop* ingredient, which kills the eggs and causes the female flea to lay sterile eggs. The water-based formulas are slower drying (alcohol speeds up drying process because of evaporation) but are the choice for irritated skin. The water-based formulas contain coat conditioners. The alcohol-based formulas dry quickly and the alcohol has a flushing effect on the fleas, which tends to create a faster kill. Some cats may drool upon tasting the spray on their coat. This may occur with alcohol- or water-based products. This response is generally self-limiting.