Mycelium make up the majority of the fungal body and consist of millions of tiny threads that spread out and bind together as they take over a host.
Did you know the fungal kingdom is larger than the plant and animal kingdom combined?? And, you can grow your own edible mushrooms at home. To figure out the ideal growing conditions you need to be aware of the three different stages:
Requires a temperature of between 28 - 30°C, complete darkness, and almost 100% humidity
Pinhead formation (when mushrooms begin to form)
Temperature should reduce to 22-24°C, indirect sunlight required and humidity remain the same.
Cropping (mushrooms reach maturity)
Same conditions as above, but humidity should drop to between 90 and 95%, and some fresh air introduced.
There are some awesome time lapse videos around documenting the life cycle of fungi. This one from David Attenborough's The Private Life of Plants is brilliant: