It’s not smart to leave cyanide lying about on public land.  Cyanide is a potent toxin that, in small amounts (i.e., <1 g), causes lightheadedness, giddiness and rapid breathing, progressing to stupor, spasms, convulsions, and death. Symptoms of acute sodium cyanide poisoning develop rapidly. A published study conducted by personnel from the U.S. Fish and Wildlife Service in the 1980s used M-44 devices (see below) and penned dogs and coyotes to establish a timeline. Symptoms develop at 32 seconds of exposure. Animals are dead within two minutes.