Rainbow Cichlids Behaviour

[ask a stupid question]

My two Rainbow Ciclids have been behaving in strange ways. Recently they have been picking up mounds of sand up and have been constructing what looks to be a giant pyrimid. any idea what there up to?

 

[Dwarfs]

Most likely getting ready to spawn I've never kept cons, and now that I have rainbows, I never will My rainbows spawn quite regularly, and they take awesome care of their fry