I once was asked by a kindergartner if clams sleep. I was stumped, and we actually have no idea! We know many bivalves have strong biological clocks, often showing circadian rhythms in activity. But as to whether they sleep? No one knows! #clamFacts
@dantheclamman OK, we may not have an answer for clams yet. But the bigger picture may give us an educated guess that they do sleep. Articles that I saw in the past few years indicate that as studies expand to simpler forms of life, so far they always find a sleep or sleep-like state. This article quotes a neuroscientist, "If it's alive, it sleeps." https://www.science.org/content/article/if-alive-sleeps-brainless-creatures-shed-light-why-we-slumber
AAAS