to kill or not to kill? that is the question.

[Marc]

Here you go

Ticks are parasitic organisms that survive off the nourishment provided by the blood of a host organism. Although most people regard them as pests, ticks play an important role in keeping balance in the ecosystem. So even though they are regarded as one of the nastiest, most unappealing insects on earth, their role in the ecosystem is an important one.
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Ticks are opportunistic and will feed on any host available; however, ticks are quick to exploit sick, weak and old animals. When ticks infest an animal in a weakened or debilitated state, they take energy from the host, weakening it even further. In turn, when ticks infest the host, it creates a downward spiral and eventually leads to the death of the host either by the ticks themselves or by other natural predators. [they assist natural selection in doing the dirty work of keeping a species healthy]
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Ticks also play an important role in the food chain of an ecosystem. Ticks and other small parasitic insects are a favorite food of birds which will often pick engorged ticks right off the body of host animals. Ticks also fall as prey to a number of predatory insects like spiders and parasitic wasps and are often infected by predatory species of nematode and fungus. Ticks are a strong and important link in the food chain as they take nourishment from large host animals high in the food chain and transfer that energy down the chain to lesser organisms.

All things within a system have multiple functions, or else they would not exist. Some functions are a bit emotionally charged to us, but regardless they do serve a function. :p

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And I wouldn't mind killing a tick that was stuck to me. It's a matter of survival, not prejudice.