When I was figuring out how to design the layout for my 20L tank, I got driftwood for one side and used some old rocks I had laying around to create a cave structure for the other side, but it seems like the majority of my fish prefer the side of my tank where the driftwood is. I recently bought another driftwood, so I'm wondering, should I take out the rocks and replace with more driftwood? Do fish prefer wood over these rocks?Thoughts?

(Not sure it's relevant, but tank is just under 2 months old.)