Toddler Biting Zippers, everything :(

Our son is 2.5, and in the past few months has started biting zippers and honestly biting everything. The second we put a pair of zippy pajamas on, he grabs the fabric and tries to bite the zipper. He even tries to bite the zipper of his 6m old sister’s zippy pajamas too. He’ll bite towels, crayons/markers, and a plethora of different things too. Not eat, just bite. If I ask him “what do we bite/eat?” He’ll say “food!” Because I’ve said it over and over and over to him when he’s biting a non-food object. He also occasionally bites my husband in the heat of the moment, when they’re roughhousing or having a lot of fun. He has never bitten me, only my husband.

Does anyone have any insight into this behaviour? It’s like the second he sees a zipper he wants to bite it. He was always a kid who explored mouth first - those touch and feel books are all worn around the feely patches because he would lick them, especially something like the rough side of Velcro. I guess I just expected him to be past this by 2.5, and it seems like the behaviour has ramped up recently, not that he’s always been this bitey with zippers, or his dad.