Poaching and (legal and illegal) wildlife trade are another common threat to animals. But the introduction of ban and / or restrictions on international trade in many endangered species (CITES) several decades ago became an effective measure in halting this problem. International wildlife trade has also been closely linked to drugs trade. In one of the most outrageous cases of simultaneous drug and wildlife smuggling which occurred at Miami Airport in 1993, 312 boa constrictors that arrived from Colombia were found carrying inside them 39 kilos of cocaine. All of the snakes eventually died.