Poisoning is probably the most widely used of the conventional techniques, as it requires the least effort, and capable of destroying a local population, though reinfestation given the mobility of the animal is almost inevitable. Laying baits of pollard laced with a phosphorus-based poison, such as "S.A.P." manufactured by Sayers, Allport & Potter, was an early method. The advantage of phosphorus is that in dry weather, assuming it has not been laid in clumps (obviated by use of a poison cart), it soon degrades to innocuous phosphoric acid and presents no further danger to livestock or pets. It does, however, present a real fire risk, and concentrated fumes can be toxic to operators.