Might be that we have more precise door builders than other parts of the world but from a German perspective that gap is huge and I don’t think I have ever seen one that tall on regular internal doors (as opposed to e.g. outdoor shed doors or similar places where insulation is taken less seriously).
¼" to ½" is all most cats need. They are surprisingly flexible
Since cat skulls are 1.5-2" in the smallest dimension, big X to doubt on this one. Unless your cat can deform it’s skull like a squeaky toy
https://www.youtube.com/shorts/qFzdp4iaQhs
definitely more than 1/4"
Might be that we have more precise door builders than other parts of the world but from a German perspective that gap is huge and I don’t think I have ever seen one that tall on regular internal doors (as opposed to e.g. outdoor shed doors or similar places where insulation is taken less seriously).
I’m in california in a shitty apartment and the door gap is the tip of my index finger to the first knuckle. Maybe 3/4"
It’s called an undercut, most are 1" and are to allow for air movement.