Is this normal?

Every day at 3 pm my son will lay on the same part of the floor in the living room just whining. Almost like he’s bored or hungry or wants something but I can never figure it out. I offer food, I even offer to play with him but he just doesn’t want any of that. Yet he still lays there just throwing a mini tantrum. It’s not constant whining it’s just whining here and there. I don’t understand why he’s doing this. Does anyone else’s kid do this? Is this a normal phase kids go through? He naps once a day anywhere from 1-3. But once he wakes up and is awake he does this. I know he’s not tired. I know he wants something, but we can never figure out what it is.