We have a 4 yr old female JRT that can be very aggressive to strangers until they show her they are harmless. She has’nt bit anyone but there have been times when I thought she might.
Our Jack male is of the mini-type, a puddin’ actually.
A lot of bark (really loud) but just 12 pounds. He lets us know when someones at the door. :)
He should be 10 pounds and we’re working on that. He’s a big time sleeper, kind of like a cat. He loves to cuddle and wants to be on a lap at all times. He hangs our with his 70 pound lab mix sis just fine.
I understand the standard-size Jacks are more energetic. We’re doing fine with our couch potato.
I had the same exact situation with a JRT. One day my son (5YO) was sitting on the floor eating popcorn. The dog was around, wasn't being fed the popcorn. My son stood up, bent over and picked up the popcorn bowl and the dog snapped at his face.
The dog was gone the next day.