How do you know your puppy has to poop?

Or maybe the question is more, does your dog also become a landshark demon until you take them outside and what do you know, they had to poop? (and no, I don't mean the obvious smelling the ground intensely while walking in circles).

For context, my 15 week old Golden Retriever has been great for the past 1-2 weeks of going to the door when she needs to pee. But when it comes to poop, it's like a switch has turned and she goes from cuddling/playing/sleeping sweetly to a possessed landshark immediately biting my arms, hands, ankles, feet, clothes, anything she can get her mouth on, really. She's not hurting me most of the time, it's just like a 0 to 100 energy shift.

I try to make sure she gets 16-20 hours of sleep a day and is not over/under-stimulated as much as possible. This specific type of biting is different than when shes overtired since that's more playful/accidental.

I mainly ask out of curiosity as this is my first Golden Retriever and puppy that is 100% mine and mine alone. My childhood dog (terrier/chihuahua mix) has always been a "freeze and look guilty" type where she moves slowly until she poops and has immediate zoomies/burst of energy. My sister has a lab/great pyr mix and a super mutt (German shepherd/border collie/golden retriever/doberman/american Staffordshire terrier/etc. lol, the list goes on) I've spent endless time with and they never seemed to do this, even as a puppy.

Hopefully she'll outgrow this and will continue to sit at the door to indicate she has to go potty lol.