I've been watching my 5 BRF jars of P. cubensis var. Golden Teacher colonize the substrate quite closely (and quickly i might add). I have observed that the mycelium expands quite a bit more rapidly in the day time while I am at work, compared to the night time while I am sleeping (barely noticeable). Therefore, it's clear to me that mushrooms (as I'm sure it has been documented) have circadian rhythms, just like human beings. I would be interested in any reading that will expand my knowledge on this topic.