Mountain goats living in the Olympic National Park are now being removed because they have developed a strong appetite for human pee.

With people routinely relieving themselves on various hiking trails at the park, located in Washington state’s Olympic Peninsula, the goats developed an insatiable thirst for urine, which serves as a strong source of salt and minerals, according to Popular Mechanics.

As a result, park authorities have begun tagging, blindfolding and airlifting the goats to the nearby forests in the North Cascades via helicopter.

Fitted with GPS collars, the goats are ferried in pairs to nine sites in the Mt.Baker-Snoqualmie National Forest, per a Motherboard report. The sites should provide a more hospitable environment for the surging goat tribe where they can roam free of human interlopers.

The NPS aims to reduce the goats’ numbers dramatically, to the tune of “approximately 90 percent of the projected 2018 mountain goat population, or approximately 625 to 675 mountain goats,” per an Environmental Impact Statement.

With minerals necessary for their diet scant, the goats have developed a strong predilection for human pee and sweat, which they can find in abundance while foraging through the park’s 1,442 square mile domain. The NPS maintains, however, that urine has an adverse effect on the goat’s behavior:

Mountain goats can be a nuisance along trails and around wilderness campsites where they persistently seek salt and minerals from human urine, packs, and sweat on clothing. They often paw and dig areas on the ground where hikers have urinated or disposed of cooking wastewater.

Goats that “paw and dig” at the earth have posed a detriment to the environment, according to the NPS. Unrelated to lapping up urine are the general safety concerns of interacting with a swelling goat herd: a hiker was gored to death at the park in 2010, for instance.

“The nature of mountain goat-human interactions can vary widely, such as humans observing mountain goats from several hundred meters away across a ridge, mountain goats approaching visitors, hazing events and hazardous interactions such as the October 2010 fatality,” the report states.

Authorities cannot implement fertility control, largely because the animals are so hard to corral. There’s also no approved contraceptive available to quell their birthrates.