There is a question here asking if sea sponges are Kosher. The answers seem to center around the idea that regardless of if they have animal cells, a halachic classification might depend on how it appears (and coral, for example, vaguely look like some sort of plant).
As a followup, are plants that exhibit rapid plant movement such as the venus flytrap, which have moving parts to eat insects considered to be animals in that they wouldn't be Kosher due to this characteristic?
