A friend of mine currently has 23 spiders in various tanks and tubs. Tarantulas, Goliath Bird Eating spiders etc.
She was telling me that she once had a Goliath (i think) that discovered it could push the lid of her tank off and escape. Apparently this happened one day and the window was open in the bedroom.
From Google (I guess this is almost fully grown)..
I was missing for a couple of days and one day my friend was sat in her living room when she heard a little girl outside ask her mum "Is it real?" - instantly realised it was probably the spider and managed to run outside and grab it. Unfortunately it died a month later!