Ticks are small blood-feeding parasites that can transmit diseases to people. Some types of ticks perch on the edge of low-lying vegetation and grab onto animals, and people, as they brush past. Other ticks are associated with rodents and their nests and may only come out at night to feed. Once aboard, ticks crawl until they find a good spot to feed, then burrow their mouthparts into the skin for a blood meal. Their bodies slowly enlarge to accommodate the amount of blood ingested. Ticks feed anywhere from several minutes to several days depending on their species, life stage, and type of host.
If you find a tick attached to your skin, there's no need to panic. There are several tick removal devices on the market, but a plain set of fine-tipped tweezers will remove a tick quite effectively. See step by step instructions here.