They are so quick sometimes and so little that things can happen. When we first got Zoe, my 3 year old was outside and I was trying to get him to come in and I opened the back door and he wasn't there and then I went to the front door and brought him in. a minute or two later i notice Zoe was not underfoot like usual!
She had snuck out the back door when i had opened it. Luckily she was just out back and hadn't gone beyond my back yard but it really scared me! She's so sweet noone would want to bring her back. She's is microchipped but you never know! Since then, I've been a lot more careful - even though I thought I was being careful then. I am always the 1st one to go out and she has caught on to that and thankfully doesn't try to scoot out 1st anymore.