They crawl out at night to suck human blood, returning to burrows in mattresses, walls and even electric sockets.

Experts say bedbug populations are growing worldwide, especially in popular travel destinations like Summit County.

A Breckenridge homeowner, who asked not to be identified, has a $300,000 property that would have been on the market this year were it not for an infestation.

“I’m not selling because I don’t feel I can sell in any good conscience without disclosure,” this person said. “And I have heard about it in several complexes. I’m not naming anything because I don’t want anybody to hate me.”

Michelle Wilson, the community nursing manager with the Summit County Public Health Department, said that because the bugs aren’t known to carry disease, there isn’t a tracking method in place.

“I know this sounds like a weird thing, but it’s not like where we would inspect for the Hanta virus,” she said, referring to a potentially deadly disease carried by rodents.

Her advice is that if residents have bedbugs, they need to get expert help.

But the critters are too small to be easily spotted with the naked eye.

That’s why Walter Penny of Denver and Ginger, his bedbug-sniffing beagle, went into business this summer as Colorado Bed Bug K9.

“Human accuracy is pathetic. Dog accuracy is crazy good,” he said.

The bugs aren’t a sign of filth and can be found anywhere — from the most luxurious hotels to the most dilapidated slums, he said.

Known scientifically as cimex lectularius, the bugs haven’t been confirmed to carry infectious diseases — but the emotional effects can be disturbing.

“They can really send some people over the edge,” Penny said.

He said they can be picked up in hotels, dormitories and just about anywhere people live. They can travel from one piece of luggage to another on an airplane.

“And they’re fast, too. They don’t fly but they can scurry like nobody’s business,” he said.

Penny said the pests can be a burden to eliminate because of their high mobility and ability to go months without blood. It can be tough to detect them until welts appear on a person’s skin, at which point the infestation is significant.

The bedbug-sniffing dog business aims to catch the problem at a residence or hotel before it’s widespread. Penny said they can sniff out 40 to 50 hotel rooms in a day.

“Say we’re at a hotel room — a one-bedroom studio — and we go around and she makes two hits. We go through again. I’ll put some markers down,” he said. “When I’m done, I’ll come back to that room, and I’ll try to find them myself.”

He said that even if he can’t spot the tiny creatures, he’ll defer to Ginger’s nose.

Ginger, about 15 months old, was picked up from an animal shelter and trained by the Florida Canine Academy — a place where dogs are also trained to detect molds, drugs and fire accelerants.

She’s received between 700 and 800 hours of training in bedbug detection, Penny said.

He said that though the service is common along the East Coast, he doesn’t know of any other such business in the Rocky Mountain region.

The business works solely to detect the bugs; if infestation is discovered, the methods for dealing with the problem are wide-ranging.

Dale Nesbit, manager of Mountain Pest Control (based in Glenwood Springs and servicing Summit County) said there are several materials on the market for treating the bugs.

“The hard part is finding out where they’re nested,” Nesbit said. “You can have a couple of them or you can have hundreds of them.”

He said they’ve been found in light fixtures, the seams of a mattress and the small crevice where a baseboard meets a wall.

High heat and below-freezing temperatures can kill the bugs, as can a number of chemical applications. Insect growth regulators can keep the bugs from reproducing.

An infestation ordinarily requires multiple treatments, he said.

“They do lay eggs, generally every seven to 10 days ... Treatment should be within that period,” Nesbit said.

The problem won’t necessarily be eliminated just by throwing out infested furniture, as the bugs could be in other areas.

Penny said a good way to prevent bedbugs is by not picking up furniture left on streets. He said old chairs and mattresses can be a disaster waiting to happen.

“Slash it up, make it unusable. I’ve broken furniture before,” he said.

Nesbit said the number of tourists and workers who come from far away is contributing to an increase locally.

“It’s gotten worse throughout the U.S. and the world, to be honest,” he said.

Because there’s no official data on infestation rates, it’s difficult to say how many homes and hotel rooms in Summit County are nesting grounds.

A team of South Dakota nursing students looking to conduct a community health assessment was directed by Summit County Public Health this week to come up with health-education information regarding bedbugs.

An informal tracker is available at www.bedbugregistry.com. It lists many addresses known to be infected in the Denver metro area, but none for Summit County.

Penny said this type of site, as well as travel sites reviewing hotels, can be difficult to trust because they aren’t necessarily confirmed. His service, which claims 90-percent or better accuracy, ranges from $250 to thousands of dollars, depending on the size of the area to be inspected.

He offers the inspection services across the state.

A $50 million bill was introduced in Congress this year with aim to provide states with grants to support bedbug inspections.

But the legislation has received widespread criticism because bedbugs are perceived by many to be a tenant’s responsibility, Penny said.

Robert Allen can be contacted at (970) 668-4628 or rallen@summitdaily.com.