Liberty 50 Plus IGR Spot-on for Puppies - 3 Month Kills 5 different types of pests on dogs - fleas, ticks, mosquitoes, lice and mites. Kills, repels and prevents re-infestation of fleas for up to 5 weeks. Kills flea eggs and larvae for up to 8 weeks. Kills, repels and prevents re-infestation of ticks for up to 6 weeks. Kills or repels mosquitoes, lice and mites on dogs for up to 4 weeks.