I have been buying Hartz Ultraguard Pro Flea and Tick Drops for years. I buy the Harts brand mainly because the product works. It kills Fleas, Larvae and Flea Eggs plus Deer Ticks and prevents re-infestation for up to 1 month. Now I have to be honest, my long haired cat has not had fleas in her mere 4 years of life, but I believe it's because I apply these drops in a timely fashion so that she doesn't get them in the first place. Now I don't apply it exactly as it suggests on the box, I apply it every 3 months in the winter and every 1 or 2 months in the warmer months (which obviously, I'm not recommending, but it works for me!). The drops are so easy to apply. You just twist the cap on the applicator to open and apply the whole tube as per the instructions. My cat tries to lick it off even though I have applied it to the back of her neck, but at best, she is only semi-successful. Another great thing about this product, it is quarter of the price of Frontline which I have also used in years gone by with other cats (however it was prior to having children and I had more money in those days). My cat has no reaction to the treatments, ever!