My oldest son Jack insists he’s telling the truth. His blue eyes are serious, and his lower lip is out. He doesn’t like it when I question his information.

Jack, you see, is six. And when it comes to the workings of the world, he’s more than happy to “add some color” — or as we adults call it, “bullshit.”

I ask, “You’re serious?”

“Daddy, I’m telling you — Dylan has caveman eyes.” He nods to his little brother, who listens intently. “Dylan’s eyes are like a cat’s. Like a caveman’s. He can see things in the dark that we can’t.”

Dylan is three. He listens, then looks at me with his enormous hazel eyes. “Yeah.”

I throw up my hands. “If you say so.”

***

The other week, the boys and I hiked through Edgewood Park. When you get to the top, you realize just how special this place is. It’s easy to imagine young lovers sitting on a blanket and taking in the sweeping views, or maybe a spiritualist sitting under an old oak, contemplating the meaning of life.

But with Jack, you’re pulling apart “wild-animal scat.”

Twigs become our instruments. Jack crouches on all fours to get a good look. “You see, Daddy. There’s no grass in this scat. It’s just all black, with some hair.” He pauses, thinking about it. “Wild-animal hair.” He looks up and scans the pristine hills. “This is carnivore scat.”

Dylan is between us. He looks at Jack, then at me. “Yeah, Daddy.”

I ask Jack to remind me what a carnivore is. For our naturalist son, it’s an easy question, but I can’t help myself.

“Daddy, a carnivore eats meat, and a herbivore eats vegetation, and an omnivore eats both.” He looks up to the clouds for a second then returns to look me in the eyes. “There’s also something called a threetavore.”

I wrinkle my brow. “A threetavore?”

“Daddy,” he says, throwing a hand into the air, “a threetavore is an animal that eats three things — meat, vegetation and something else.”

Dylan looks at Jack, then at me. “Yeah.”

“Wow,” I mumble. “Had no idea.”

***

This weekend we watched as our new cat, Tucker, sat on a window ledge and gazed at the squirrels on our fence. Only a flimsy screen separates our 6-month-old kitten from the puffed-out squirrels that have been fattening up on acorns from our oak tree. Tucker acts like he’s just escaped a 14th Century prison and is seeing a woman for the first time in 30 years. His mouth is open. His ears are perked. His eyes are wide. A chirping noise escapes from the base of his throat.

“Is Tucker a threetavore?” I ask.

Jack sighs and rolls his eyes. “Daddy, everyone knows cats are omnivores. They like meat, but they also like things like grass and vanilla ice cream and tuna.”

I open my mouth, then bite my lip. I think I’ll wait a little longer before pushing the matter. In Jack’s world, threetavores can exist a little longer.