Trump Admin Opens Door to Resumed ‘Cyanide Bomb’ Use on BLM Land

A new memo abrogates a Biden-era ban on the controversial devices.

A cyanide bomb. Photo Credit: Brooks Fahy

The Trump administration has quietly opened the door to the resumed use of so-called “cyanide bombs” on Bureau of Land Management parcels across the country, according to an internal April 2026 memo. The memo shows that BLM has effectively abrogated a Biden-era ban on the deployment of the controversial devices on the agency’s land.

M-44s, also known as “cyanide bombs”, are poison traps — spring-loaded devices that spray a powder of sodium cyanide when triggered. They are used by USDA’s Wildlife Services — a federal agency that conducts predator control programs — to kill coyotes and other animals that interfere with ranchers and other industry groups.

M-44s gained national notoriety in 2017 when 14-year-old Canyon Mansfield and his dog were sprayed by a cyanide bomb that had been placed in the hills behind the Mansfield family home in Idaho. The dog, Kasey, collapsed and died while Mansfield was rushed to the hospital and survived.

In 2023, the Biden administration barred Wildlife Services from deploying M-44s on BLM lands, a move that was cheered by conservation groups.

The new memo between BLM and Wildlife Services appears to abolish the Biden-era directive. It no longer contains the Biden-era language that prohibited M-44 use on BLM land. Rather, the new memo specifically contemplates their revived deployment on BLM land, directing Wildlife Services to provide notice to local BLM offices prior to use “of restricted-use pesticides such as … M-44s that deliver sodium cyanide.” The memo will remain in effect until 2031.

You can read the April 2026 memo here.

“These devices are indiscriminate killers and cannot be used safely,” said Brooks Fahy, the executive director of Predator Defense, who has long campaigned against M-44 use and first obtained a copy of the April memo. “We are going to fight this tooth and nail.”

The Interior Department, in a response sent to Public Domain after publication, stated that the April 2026 memo between BLM and Wildlife Services “identifies restricted‑use pesticides—including M‑44 devices—as tools that may be considered under existing law and environmental review. The MOU does not itself authorize or expand use of M‑44s; any proposed application requires advance notification to BLM, compliance with NEPA and other statutes, and must conform to all laws and regulations. BLM will continue to evaluate proposals case‑by‑case and may prohibit or restrict such tools where warranted to protect public safety, pets, wildlife, and designated lands.”