Thats amazing! Ive definitely heard stories of them figuring out how to get prey out of enclosures (jars, plastic eggs, empty soda bottle, etc) but i never heard of one stepping out of its tank for a meal and comming back! They are extremely inquisitive creatures... and learn pretty quickly. Doesnt suprise me at all that the bimac got the best of that mantis.... octo is a very efficient predator.