Re: Wot about the mice ?
Mice can chew through copper. Their teeth are hard and sharp. I've had mice gnaw away enough of a Longworth Small Mammal Trap* to escape through! (They're made of ~1mm sheet "aluminium". I have no idea which aluminium alloy is used!)
*That used to be my house mouse trap of choice, but I'm not sure that I want to spend another 60 quid on infrequent visitors. Maybe I should await the arrival of cheap Chinese robo-mice with bee stinger attachments to discourage future interlopers.