LOL Dogs are incredible clever when it comes to getting at someone else's food! Never underestimate their ability to search it out and conquer any obstacles in the way. 
My dog searches under the cupboards for any crumbs we leave behind because, you know, we do not feed her enough. HUMPH! The other day I found her smelling at the bottom of the doors where the Cheerios box is kept. I am sure if I left her there she would figure out a way to open the cupboard.
Good luck keeping the iguana fed now that the Chihuahua knows where the goods are.
| 
