(CBS4/AP) – The annual migration of tarantulas is underway in Southeastern Colorado. Officials say the Oklahoma brown tarantulas migrate through La Junta, about 176 miles southeast of Denver.

FILE: A tarantula in a terrarium in Pfedelbach, Germany. (credit: SEBASTIAN GOLLNOW/AFP/Getty Images)

Scientists say the majority of the spiders are 10-year-old males looking to mate with females hidden in Colorado’s grasslands.

(credit: CBS)

Officials say the peak time to view the migration is mid-September near Comanche National Grassland south of La Junta off U.S. Highway 109.

Officials say tarantulas are mostly harmless to humans, but have bites that can cause injury or allergic reaction and hairs that can be irritating to the eyes, mouth and nose.

(© Copyright 2021 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)