I just got two kittens – Petra and Pandora… they are just at 12 weeks old, but have fleas, so I used some Hartz (for cats and kittens 10lbs or under) that I had purchased a few weeks ago (in anticipation of getting my sweet girls)… I applied the drops at around 5pm… then, at around 10… Petra started first – I noticed that she was walking funny – almost sideways, and she looked like she was shivering, but it was more intense than that… not a siezure, but muscle spasms – even her little ears and tail were shaking…. I washed her off and dried her and gave her water with a dropper… then went to check on Pandora – who seemed to be fine at first, but soon after also experienced the all over body shaking… I washed her and dried her… Gave each of them water throughout the night and kept them wrapped up. They are at the vet right now, getting another bath and receiving atropene to help relieve the tremors.. Maybe even some Valium… These are KITTENS for goodness sake! They shouldn’t have to go through this! Hartz is very irresponsible for allowing this product to continue to be sold, and I, for one, will never use ANY of their products again… I have told everyone I know the same thing…. No one needs to go through the worry I went through last night, particularly when they are just trying to be good to their animals….