Infestation of field mice called worst ever

In what’s being called one of the worst infestations of field mice ever on the Westside, thousands of the rodents are invading the district, threatening to spread disease with their fleas and property damage with their sharp teeth.

Since June, Waimea has filed the most complaints with the state Department of Health, Vector Control, said Leroy Tangalin, Vector Control supervisor for Kaua’i.

However, Tangalin said, the problem is island-wide because mice can migrate.

Field mice are coming from the dry hillsides and into Westside communities looking for food and water, and Waimea seems to be their town of choice.

“If you don’t have food out there and it’s dry, they’re gonna go into the community and look for food and water.” Tangalin said.

The problem started last summer, said Tangalin. He attributed in part the multiplying mouse population to the closings of sugar cane plantations.

When irrigated, fields provided food and shade, a perfect place for mice to stay during the summer, typically the months when rodents multiply, he said.

On Maui, mice have infested Kihei, Kula and the grassy former cane fields above Lahaina town. On the Big Island, highly affected areas include Waikoloa, Kawaihae and South Kohala.

Mice and all rodents are associated with diseases such as leptospirosis, murine typhus and salmonellosis, bacterial diseases that can have effects such as high fever, diarrhea, jaundice and headache.

However, the state Department of Health does not see an outbreak of the diseases from the current field mouse problem.

Tangalin said that on Kaua’i, vector control workers are trying to keep the rodents under control by setting “tin cat” traps. They insert about six pieces of pellet dog food to bait the traps. During a one-night survey on June 27, 92 traps were set, catching 277 mice. They often found 10-15 mice in one trap.

Kaua’i vector control workers have also placed about 150 bait stations in Waimea, Tangalin said.

Though house pets might be able to find the traps, it’s not possible for them to actually get to the poison bait because of the small size and location of the entrances to the traps, he added.

Mice are often not seen during the day, so their presence is usually detected by fecal droppings; gnawed holes in food containers, window screens, water hoses, and wall openings around utility pipes; and dirt or grease marks along walls and pipes where rodents travel, said a prepared statement from the DOH.

Making sure mice do not invade your home is simple. Clean and maintain your home, especially the kitchen. Wash dishes, clean counters and the floor and keep food covered securely. Remove mice’s potential food sources. Keep a tight-fitting lid on garbage; throw away uneaten pet food at the end of the day, including bird feeders and fallen fruits or nuts.

Tangalin noted that store-bought traps are efficient at getting mice. However, poison traps should never be used indoors.

Spring-loaded or glue rodent traps should be placed near baseboards because rodents tend to run along walls and in tight spaces rather than out in the open. Mice will eat just about anything, and they do tend to like dog or cat food. Traps will work best when all food sources other than those on traps are removed.

The only way to help control the spread of fleas is by removing the dead rodents quickly. Fleas will leave a rodent a day or so after the rodent dies and will seek out other food sources. That is how they can spread disease.

Mechanical traps are best used outdoors. Do not place them where pets or children can access the traps. Read and follow all label directions for safe handling and use or consult with store management for product use.

Prevent a mouse’s entry into your house by sealing any entry holes with mesh metal screen, sheet metal, cement, or other patching materials. Mice will commonly enter under doors and unscreened windows or holes put in walls for water pipes.

For further information call the Kaua’i office of the Hawaii Department of Health at 241-3306.

Staff Writer Kendyce Manguchei can be reached at or 245-3681 (ext. 252).


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