We have a house with a front door, a side door, and a back door. We have a 6' wooden fence around the back yard, not affecting the side or front doors.
Our second pet, Spicer was an inch over standard and used that inch when it served his purpose.
He was VERY afraid of fireworks, and afraid of thunder, but we think he thought they were from the same thing.
Once he was still out as the fireworks started (and it was neighbors) he climbed the fence and was jumping at the back door. Such a good boy, he could've run away.
Captain was afraid of the central vac, I tried to use it when it was nice out and he could run to the way back yard.
Freida was more jumpy around noises she wasn't expecting. She was born that way and stayed that way her whole life. I figured it was because she had quite a bit of African in her none of the others did), and she would need that trait to survive in Africa - I'm just guessing though.