Tiny ticks are turning into huge pests this spring for hikers in the Foothills and desert of southwest Idaho.

It’s not that there’s an unusually large infestation. But the cool, moist spring is prolonging their threat, biologists say.

Ticks - two-tenths of an inch across - are not insects, but are related to spiders, mites and scorpions. The much-feared Lyme disease is not a great risk in Idaho, said state epidemiologist Dr. Jesse Greenblatt.

But three other ailments carried by ticks are of concern: relapsing fever, Rocky Mountain tick fever and Colorado tick fever, although the diseases are relatively rare.

The most common: 15 cases of relapsing fever were reported in North Idaho last year.