TOLEDO, Ohio — A zoo in Ohio says a thumb of one of its volunteers became detached when an orangutan reached through a barrier and bit her arm.

The Toledo zoo says the volunteer’s injuries were not life-threatening and that she was treated at a hospital.

Zoo officials tell The Blade that what happened isn’t the orangutan’s fault. It is not clear how the volunteer’s digit became detached.

The incident took place Saturday in an area not accessible to visitors while the orangutans were being fed.

Zoo officials say all its great apes attempt to sneak their fingers through to grab things and that it’s a known behavior that staff must watch out for while they’re near the enclosure.