The island of Guam in the Pacific is about 30 miles long and 6 miles wide but it has a problem.
About 60 years ago it had no Brown Snakes, today? It has about 2 million!!
The snakes are mildly venomous and get everywhere and people have even found them in their beds!! But the biggest impact is on the islands wildlife. The forests are quiet with the only place many of the native birds can be seen is in cages in a captive breeding centre.
The authorities are air-dropping dead mice laced with a poison that is used as a pain reliever but is deadly to the Brown Snake.
And they now use Jack Russells to sniff every item of cargo before it leaves the island.
The islanders are trying to eradicate the snake but it may be too late.