Preventing the spread of the invasive brown treesnake is paramount. It is much cheaper than intervention once a snake population is established.
Without rigorous prevention, control (let alone removal) of an introduced reptile species is extremely difficult. In the case of the brown treesnake, prevention efforts include working to detect stowaway snakes before they leave the island, as well as extreme vigilance on islands where the snakes are most likely to invade.
USGS scientists and staff associated with the Brown Treesnake Project at the Guam National Wildlife Refuge work on developing and testing control tools for invasive brown treesnakes, as well as understanding their impacts on Guam's ecosystems. Project staff also lead the multi-agency Brown Treesnake Rapid Response Team, which responds to invasive snake sightings throughout the Pacific and trains personnel from cooperating agencies to increase the capacity of the team.
If the brown treesnake gets to any other snake-free islands, it will find a veritable banquet of prey animals, and the same devastation of wildlife could happen there as has happened on Guam. Getting ahead of the curve and implementing prevention efforts from the beginning are essential, before an alien species becomes a problem.