Mystic - Coyotes decided to den this year in the Ocean View area of Mystic, so neighbors sometimes hear howling at night.

Groton Animal Control Officer Donna Duso said cat owners should keep their pets inside, and that advice applies townwide. Duso also urged pet owners to have a microchip placed under the animals' skin in case a cat or dog gets lost.

"If you love your cats, they should be indoor-only cats," Duso said. She said she's seen no overall increase in the number of complaints about coyotes, and she expects those in the Ocean View area will move on by the end of August or September.

Chris Vann, a wildlife biologist with the state Department of Energy and Environmental Protection, said coyotes remain a significant problem in areas with large tracts of land, such as Fairfield, despite a decline in the number of complaints since 2009.

"We hear about dogs being injured or killed, sometimes on a weekly basis," he said.

The wildlife division reported 350 coyote complaints statewide in 2009, 250 complaints in 2010, 215 complaints in 2011, and 212 complaints in 2012, he said.

Prior to 2009, Vann said, the number of coyote complaints had been increasing steadily for 15 years.

In the Mystic and Groton area, Vann said, the department received complaints in February about coyotes on Irving Street and in the Haley Farm area. The department also got a call about a coyote barking at someone walking a dog at Haley Farm.

In May, the department heard about coyotes on Old Evarts Lane. It also received a report of coyote pups gathering in a den near a yard on Rose Lane.

Hanneli Ansel of Mystic wrote in an email that his and his friends' cats disappeared this spring like "smoke in the air." He also saw notices for two lost small dogs, he wrote.

The coyote population is highest in summer and fall and tends to affect communities with areas of open land or pockets of woods, though the animals may appear on the fringes of populated neighborhoods, Vann said. Coyotes eat mostly small rodents and rabbits but also can kill deer, Vann said.

Coyotes building dens may exhibit predatory behavior toward small pets, such as those weighting 10 to 25 pounds, and territorial, aggressive behavior toward large dogs, he said.

He said residents should report coyote attacks or attempted attacks on pets, sightings of coyotes in yards or neighborhoods, and any coyote digging through garbage, waiting around a trash receptacle or acting unafraid of people. The DEEP Wildlife Division number is (860) 424-3011.

d.straszheim@theday.com