The latest strategy Friday to lure in the elusive alligator out of the Humboldt Park Lagoon involves playing recordings of baby alligators.

“That’s one of the things trappers use in Florida. Give a distress call of a baby. It attracts adults in the area to come investigate,” said Frank J. Mazzotti, one of the self-proclaimed “Croc Docs” at the University of Florida. Mother gators will approach to protect the young, he said. “But if it’s not a parent, the outcome could be different.”

The strategy has worked “very well” with wild alligators in Southern states, said Alligator Bob, the volunteer who’s become the public face of the rescue. But Humboldt Park’s alligator probably was raised in captivity, according to Bob, who serves as a member of the Chicago Herpetological Society.

“We’re not putting a lot of success in it,” Bob said. “It’s worked well in the wild, but we don’t know if it’ll work here.”

Mazzotti has been advising Bob and Chicago Animal Control and Care on next steps in the rescue, department spokeswoman Jenny Schlueter said.

Meanwhile Bob — who late Friday admitted to feeling “exhausted” after four days of the hunt — also has been trolling the water with a medium-weight rod and reel with treble hook — that’s a hook with three points.

The experts don’t know when the creature — identified as an American alligator — last ate, and worry it is too nervous to eat.

So the Chicago Park District has shored up fencing around the lagoon to keep bystanders away, Schlueter said.

“The noise is affecting the chance of the alligator surfacing,” she said.

Meanwhile, the Illinois Department of Natural Resources is installing underground fencing to try to corral the animal into a smaller area where it is more likely to be trapped.

“If we can localize where he’s at, we can concentrate any type of action there,” Bob said.

If authorities can confirm the gator is close to the boathouse, they will set a barrier under the bridge that leads to other water ways, including beach areas.

Bob hopes the gator will become comfortable enough to crawl onto the rocks near the boathouse to sunbathe, so they can get a good look at it.

The weather also hasn’t helped efforts to spot the reptile.

”It’s been very windy, so he’s probably been hiding in one of the swamp areas and he doesn’t want to play,” Bob said. “So at the moment we’re looking at alternatives.”

The air temperature dipped to 46 degrees last night while the water stayed around 74 degrees, Bob said, making him fairly certain that the gator stayed underwater to keep warm.

He said this lagoon is paradise for the alligator.

“I was out at 5 a.m. and this lagoon looks like Costa Rica. It’s beautiful.”

The alligator, Bob said, is beginning to understand it’s the biggest predator here.

Think of a person who finds themselves in a huge mansion instead of their house, he said.

“He’s looking for the landlord who isn’t there.”