Oh, they can't be defeated by a door! Just stopped. Assuming they're not the kind that tries to squidge their way through the cracks.

...Mmh, but I suppose nobody actually tried to hit one with a door yet. I suppose if you trapped one half in, half out of the door at lockdown you might kill it? Or... or they might just be able to survive like that. Erm.

 

 

Uh, sorry, where was I going with this...? Darnit.