CHARLOTTE, N.C. -- It's one thing to see bats outside where they feast on thousands of mosquitoes a night; it's another thing altogether when they move inside.

“I didn't realize until recently that they were inside the house,” said Richard Morgan.

Morgan didn't see them first. He heard them through the walls of his home in Midland.

“I started hearing noises in the bathroom, scratching and squeaking,” he said.

He said the sounds were creepy, but much worse was the view in his attic -- a colony of bats, 40 or 50 in all, hanging upside down and squirming along a gable vent.

It's the very same problem Justin and Jen Watkins have had in their Belmont house since June.

“They just kept coming and coming. There were about 30 of them coming out of the roof flying toward us,” Jen Watkins said.

They called a pest control company to get rid of them.

“We thought it wouldn’t be a problem, that the day they came would be the last day we saw the bats,” she said.

Instead, they were shocked to find out the bats couldn't be kicked out.

That’s because North Carolina regulations don't allow bats to be removed from homes during breeding season, which goes from late spring through the summer, because if the holes they go in and out of are closed off, the baby bats, which can't yet fly, will be left to die inside attics. So until August, when those babies can fly away, the state says bats get to stay put.

Because dead bats can create strong odors and health hazards, pest control expert David Gentry has to explain those regulations to every customer who calls.

“This summer seems to be as much or more than any other summer that we've had. There are bats and we're getting calls literally every day,” said Gentry, who works for Trutech Animal Removal.

For now, Gentry seals up cracks and crevices where more bats can come in but leaves one opening until any babies mature.

Until then, the Watkinses will see the bats outside and hear them inside their walls.

“You know they're just right there. You know it's just one little piece of drywall between you and them and there's nothing you can do about it,” Jen Watkins said.

Fortunately , the Watkinses haven't seen any bats in their living areas, which can be much more serious, Gentry said.

“It does happen from time to time where bats get in, and the main concern with that is the risk of rabies. Because as you may know, bats carry rabies,” he said.

In that case, the state will consider allowing immediate removal. But for most customers, a bat valve is the solution.

“They can fly out, but when they try to come back in in the morning, to try to get back in, they can't get in the end,” he said.

The valve can't be installed until August, however, so homeowners just have to deal with the bats until then.

There is one other option for homeowners when bats come into a living area. Mecklenburg County's health department will get involved because of the potential for rabies. They'll trap the bats and bring them in for testing, but not if the bats stay only in the attic.