David Mikesic, Navajo Naiton Zoo via AP
This 2009 photo from the Navajo Nation Zoo shows a rattlesnake, a part of the zoo's reptile collection in Window Rock, Ariz. Cultural beliefs among Navajos about snakes has lead to the removal of three snakes from the tribal zoo.

FLAGSTAFF, Ariz. — The Navajo Nation Zoo has shipped off three snakes that were deterring visitors from seeing other animals kept in the same area.

The reason lies in cultural beliefs about snakes as bad omens.

Zoo manager David Mikesic said Friday that the zoo has exhibited snakes for decades but they've been unpopular. He says many school teachers didn't want children seeing them or even breathing the same air as the snakes.

The two bull snakes were shipped to a Utah aquarium in March, and the rattlesnake was sent to a New York zoological society last month.

Navajo medicine man Anthony Lee Sr. says watching snakes eat, shed their skin or mate can affect Navajos' physical and mental health. Navajo ceremonies depict snakes, but they're never a sign of anything good.