Tiny, Tenacious, Terrible Ticks

You can't spend time outdoors without being a target for ticks. These little vermin wait patiently on blades of grass or other vegetation for opportunities to attach to any animal, including you or your pets. Not only are they pests, their bite has the potential to transmit disease.

Only mosquitoes surpass ticks in the ability to transmit disease to animals and humans. About 850 species of ticks have been identified worldwide. They hunger for the blood of mammals, birds and reptiles. It's during their meal that they can introduce a wide array of disease-causing organisms.

Ticks are closely related to mites, spiders and scorpions. They are divided into two families: Ixodidae (hard ticks) and Argasidae (soft ticks). The soft ticks generally parasitize birds. The hard ticks are primarily parasites of mammals. They are the villains Missourians most often encounter.

A tick's life is divided into four stages: egg, larva (often called seed ticks), nymph and adult. Ticks advance through these stages by molting, during which they shed their outer skin.

After an egg hatches, the emerging larva is about the size of a poppy seed and has six legs. After a blood meal, typically from a small rodent, the larva drops off its host, casts its skin and becomes an 8-legged nymph. After attaching and feeding on another mammal, the nymph drops to the ground and transforms into an 8-legged adult. Adult ticks are 1/16 to 1/4 inch long, or about the size of a sesame seed. When engorged with blood, female ticks might expand to 3/8 inch or longer.

Soon after feeding and mating, which usually occurs on a host, the adult male dies. The female drops to the ground to lay thousands of eggs, and then she dies, too. Eggs may not hatch for several months, depending on humidity, temperature and other conditions.

Ticks are hardy parasites. Their skin is so tough it's hard to crush one. The larva, nymph and adult can survive several months without feeding. When not climbing onto low vegetation to wait for an animal or human to pass, they remain on or near the ground. Dehydration is their worst enemy. They often have to leave their perches to rehydrate themselves with ground moisture.

Questing

Ticks cannot run, leap or fly. They only crawl, and only slowly. To find and attach to a host, they use a wait-and-watch technique called questing. They climb to the top of grass stems or take a position