I still remember this episode from the 80s when sir David Attenborough climbs into a termite mound up to 6 feet below the surface.

https://www.youtube.com/watch?v=jbbLCgh6sso

These termites are fungus farmers and feed the gigantic queen with it.

Unfortunately the fungus farming is not part of this clip, but it is also described the same program.

Edit: This is an older version of sir David Attenborough, revisiting another mound and talking about fungus farming. https://www.youtube.com/watch?v=xGaT0B__2DM