Can it Rejuvenate?
Ticks have a split personality of some sort. When they frst attach, they are tiny critters and hardly noticable. Then they suck blood like bandits and swell up to 100 times their original size and look like swollen chick peas. The tick's small head can easily remain inside the flesh as the rest of the body is pulled away. Believe it or not, the head can continue to live without the rest of the body and potentially carry infection.
A few entomologists I have talked to say that the tick's head can regenerate the rest of the body while locked on, but very few studies have confirmed this. If it can, then the tick could continue to live, rejuvenate, and come back alive as if it had another life. One of the reason that tick bites stay around so long after you thought that you pulled it off is that it's head is still there working to live. Your body will fight the tick and the bite will become inflamed, but the "dead' tick may still be there because it's head is still attached to you, perhaps underneath your skin.
Most of the time, your immune system will win the battle after a couple of weeks, but believe me, ticks are tough parasites and have caused many deaths in animals because they can carry deadly disease. Those animals at risk include humans.