I was thinking more window screening. I'm not even sure if they make metal screening anymore - but I think you're right that hardware cloth they'd probably peck through. 
Could also do two layers of hardware cloth - cutting one on the bias- but that seems like a LOT of work. I'd try the toughest window screening you can buy.
	
		
			
		
		
	
				
			Could also do two layers of hardware cloth - cutting one on the bias- but that seems like a LOT of work. I'd try the toughest window screening you can buy.
	
