I dug out an old file with ants and found that those poor little creatures had trapped into neverending loop.
Rendered over night, for 200 passes per frame. Unfortunatelly some frames came still too noisy. I intentionally unchecked
lock sampling pattern in hope that i can denoise in post, but either noise areas are too small or my knowledge of working with neat video plugin is not good enough, denoised result turned out pretty awefull. Finally i decided to wait for Corona build with adaptivity and rerender all sequence again. Anyway here's dirty preview. Made for fun.