The way Frontline works is the tick has to bite the pet before it kills it. So you may still find a tick on your pet, but it should be dead (unless you catch it pretty quickly).

That having been said, over the past year we've been seeing pets come in to the clinic on Frontline covered in fleas, and we are starting to see more and more of them as the summer months continue. Until recently though the tick properties we assumed have still been working. But we had THREE pets on Monday and one on Wednesday that we found live ticks on (and there have been more, my surgery days just come to mind because I was able to search better for ticks while they were asleep and on one dog I found A TON of them...), at least half of which the owners claimed that they were using frontline. I'm starting to wonder if Frontline is just becoming an ineffective product or if the fleas and ticks are starting to become "immune", but we have been recommending to clients to try other products. I don't wish to list them here because I don't want to sound like I'm an advertisement or endorsing them, but if you do want my recommendations I'll PM you what we're doing in clinic