why is my red devil moving rocks?

  • We are currently upgrading MFK. thanks! -neo
my Oscars moved a small plant to cover part of their hiding spot, guess they just do it for fun and to enhance their environment, i put them in there new tank but they havent moved the plant yet, oh yeah and its a fake plant
 
All my red devils i've had dug like maniacs!

i'm assuming they are marking/creating thier territory.
 
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