A flight for Honolulu was being checked in, as was a Tokyo flight.

The snake, which is not native to Guam, has killed off almost all the Guam forest birds. It attacks pets, rodents and has even been found in homes, biting infants. The snake is responsible for frequent power outages when it spans the distance between power lines.

It is among the most feared potential alien pests for Hawai'i, where wildlife experts feel it could devastate native species.

A passenger apparently had prepared to take the snake on a flight from Guam, but left it at a security screening counter for departing flights. A U.S. Department of Agriculture Wildlife Services staffer interviewed people in the area, but could not identify the person who brought it.

The snake, roughly 3 feet long, was probably reproductively mature, said Christy Martin, of Hawai'i’s Coordinating Group on Alien Pest Species. It was found inside a capped plastic water or soft drink bottle about 3:30 a.m.

"A large group had just checked in for a Tokyo flight. Check in was open for a Honolulu flight, although the flight does not leave until 6:45 a.m.," said Dan Vice, a federal Wildlife Services agent on Guam.

Federal teams have established more than 3,000 traps around Guam’s ports, power stations and electrical transfer stations, and they conduct searches with dogs of outgoing cargo and vessels. The effort caught more than 12,000 snakes in 2002. Cargo and vessels arriving in Honolulu from Guam are also checked as an additional measure of security. But until now, the agency had not regularly checked passenger areas at the Guam airport.

"This is exactly the type of situation we aren’t set up to detect. Unless our staff happen to be in the area and one of the dogs walks up to you and smells it, we’ll never find it," said Mike Pitzler, of Wildlife Services in Honolulu.