WATERBORO — Don Dremsa of Arundel bent and picked yet another tick off his bare legs Monday, just after returning with a team that searched for his 15-year-old grandson, who has been missing since Thursday.

The ticks and black flies didn’t faze him. He was glad to stay busy rather than dwell on the fate of Jaden Dremsa, whose disappearance has triggered a massive search in North Waterboro that has yielded no clues.

“I have to keep moving,” Dremsa said. “It’s too hard sitting and worrying.”

Dremsa remains puzzled by Jaden’s disappearance, saying it’s unlike his grandson, a loner by nature, to wander so far. “He doesn’t like to go out too far from the house,” Dremsa said.

Officials have said the Massabesic High School student has a mild form of Asperger’s syndrome, sometimes described as a high-functioning form of autism.

Jamie Dunlap, a 14-year-old student at Massabesic High, returned from an afternoon of searching, tramping through bogs in socks soaked by water that leaked through her hiking boots.

She described Jaden as quiet, but not aloof. “He likes to make people laugh,” she said.

During lunch at school, he doesn’t tell jokes but tries to give people a chuckle with his behavior and gestures, Dunlap said. He has a small circle of friends, people he trusts and feels comfortable around, she said.

Searchers have tried to anticipate where Jaden might have gone, but there has been no indication what his plans were when he walked off Thursday, said Lt. Kevin Adam of the Maine Warden Service, which is coordinating the search. He was not despondent and gave no indication of his plans, other than his intention to climb a tree.

Jaden’s diagnosis could cause him to avoid searchers. In giving instructions to search teams, wardens said he could be in a tree, watching the search effort beneath him.

It’s not unusual for people on the autism spectrum to wander, and often they are drawn to water, said Matt Brown, an information specialist for the Autism Society of Maine.

VOLUNTEERS, CHURCH HELP SEARCH

Authorities say Jaden left his house at the Twin Pines Trailer Park, between Route 5 and the western shore of Lake Arrowhead, about 3 p.m. Thursday. A neighbor saw someone matching the boy’s description a short time later on the banks of the lake. Getting to the spot requires a walk through swampy areas, wardens said.

Don Dremsa said his grandson isn’t on social media, doesn’t have a large social circle and has few hobbies besides playing computer games. During family get-togethers, he often prefers to sit off by himself.

The warden service has maintained an extensive search since Jaden disappeared. On Monday, wardens coordinated 120 searchers, the vast majority of them volunteers who had come from across the state. The Lakeside Community Church was converted to a headquarters where volunteers could get search assignments and donated refreshments.

“It just seems like everyone wants to do something to help,” said Jaden’s aunt, Jessie Howard of Biddeford.

The church moved its Sunday services to Friendship Park so the search could continue.

Family members are increasingly anxious, but trying to stay optimistic and support each other, Howard said.

“Anyone who’s a parent and has lost their child in a grocery store or a park, even if you just lost them for five minutes, it’s sheer terror, and every moment that passes, that feeling grows,” Howard said.

AIRCRAFT FLY OVER LOWERED LAKE

Adam, of the warden service, said at a news conference Monday afternoon that an extensive search of Lake Arrowhead had yielded no results. The lake was lowered about 2½ feet Monday, exposing a forest of stumps and milfoil but no sign of Jaden.

Searchers walked the circumference of the lake while crews in a warden service airplane and a Maine Forest Service helicopter searched from overhead.

Adam said that after a thorough search of the lake, the warden service told the dam owners that the lake level could be raised.

Adam said there was no indication that Jaden was in the water, but with few clues on land, the searchers had to check it.

Search teams also revisited areas that had not been scoured, and moved on to areas that had not been searched at all. Each team carried a GPS unit to give the warden service a complete picture of the search area, which was projected onto a topographical map at the search command post, an RV-like vehicle parked outside the church.

Adam said a large number of unoccupied seasonal homes surround the lake and it’s possible that Jaden sought shelter in one that hasn’t yet been checked.

But with each passing day, searchers become more fearful they won’t find him alive.

“I can see scenarios where he’d still be alive,” Adam said. “Am I concerned? I’m very concerned.”

Search teams with about 10 people each, including at least one member with search-and-rescue training, have combed through dense woods and swamps for two to three miles in every direction from Jaden’s house and about six miles along nearby roads, Adam said.

John Leeman of Windham said his group walked through dense stands of immature pines and checked vacant houses.

Alta Harding of Standish showed up Monday with her friend Mike Cielinski of Lyman and her two black Labrador retrievers, Charlie and Cassie. The dogs aren’t trained in search and rescue but they do a good job sniffing out her nephew when he plays hide and seek, so she thought they might be able to find Jaden if he was hiding.

She said she felt compelled to help after hearing a forest service helicopter pass over her house. “It’s been on my mind since day one,” she said. “I hope it’s a good outcome.”

WANDERING AN ASPECT OF AUTISM

Brown, of the Autism Society of Maine, trains law enforcement personnel and first responders how to deal with people on the autism spectrum.

Brown said a 2011 study by the Kennedy Krieger Institute at Johns Hopkins University in Baltimore showed that 48 percent of those with autism wander at some point in their lives. Of those, 33 percent are unable to communicate.

“They wander for different reasons,” Brown said. “It might be because they are upset or overstimulated. It might be because they are fixated on a certain thing or place.”

One of the biggest education efforts of the Autism Society of Maine is for parents to fill out registration forms that are made available to 911 dispatchers, so that emergency personnel have immediate access to important information about any child who disappears, including whether the child has a history of wandering, the level at which they function, and any dislikes or triggers.

“If a child goes wandering, parents often are in panic mode,” Brown said. “They may not always remember critical pieces of information. These are always life-and-death cases.”

Brown said parents shouldn’t be afraid to tell neighbors and others about their child’s diagnosis.

“They can say, ‘If you see my kid wandering, grab him. Don’t assume everything is OK,’ ” he said.

Last month, a 10-year-old boy wandered from his home in Belgrade. A passer-by found him wading in Messalonskee Stream. If that person had not stopped, Brown said, the child likely would have been injured.

Drowning is a leading cause of death for people with autism, Brown said, because they are often drawn to water. His first piece of advice to searchers is to check water sources first.

Anyone with information about Jaden’s disappearance or whereabouts is asked to call 911 or the Maine Public Safety Dispatch Center in Gray at 657-3030.

Staff Writer Eric Russell contributed to this report.

David Hench can be contacted at 791-6327 or at:

dhench@pressherald.com