State urges residents
to keep out rodents

State health officials are advising residents on how to keep rats and mice off their properties because of worries that increased numbers of rodents could spread diseases such as leptospirosis and murine typhus.

"We're giving people notice several weeks before it gets drier," said Laura Lott, state Health Department spokeswoman.

Mice had plenty of food during the wet winter, said Glenn Sugioka, East Oahu supervisor in the Vector Control Branch.

"When it starts getting dry and natural food supplies go away, mice will start migrating and looking for food, possibly bringing them into someone's yard or home," he said.

Mice created problems last summer in Makakilo, Waianae and Makaha, and in parts of Maui and the Big Island. Murine typhus was reported -- a bacterial infection transmitted to humans by fleas that have bitten an infected rodent.

Urine from infected animals can contaminate fresh water and cause leptospirosis, a potentially fatal bacterial disease.

Lott said the Department of Health is focusing its limited resources on preventing West Nile virus from coming into Hawaii. "We're asking residents to take responsibility for their own property," she said.

Homeowners are urged to seal gaps under doors, cover ceiling vent holes, holes in the wall around sewer and water pipes and other points of entry with 1/4-inch mesh screen, sheet metal or cement.

"If you can push your flat palm under the door to the first or second knuckle, a mouse or rat can come through," said Dr. Roy T. Furumizo, entomologist with the Vector Control Branch.

He recommends using snap traps for mice indoors because they "kill them immediately and humanely."

Pet food, garbage and other food sources should be removed for the traps to work better. Traps should be checked daily, and dead mice sealed in a plastic bag or container and discarded.

Furumizo advises against using poison in the home. "If mice or rats die within a double wall, there is a stench problem for a year or so, and a fly problem," he said. "It happened to me already. A rat took revenge on me."

Rats climb, so metal bands placed around the trunks of coconut, avocado, mango and other fruit trees, six to eight feet off the ground, will keep them from food, Furumizo said.

Rats also can jump four to six feet, he said. "They're much more versatile (than mice) in terms of establishing a niche within a given area, and they're good burrowers. They can go into rock walls."

Poison can be used outdoors in holes where rats burrow, if there are no pets in the area, Furumizo said. The hole should be sealed off with rocks or boulders so the rat can't escape. "They will die in the hole, but you will have a stench problem."

Rats themselves aren't dirty, Furumizo said. "They're clean animals. They only eat what we eat. But they spread microorganisms responsible for the diseases."