Dats bouncing off rocks??

[Tigerfish908]

Does anyone elses dats bounce off the rocks? My (2) 2" thinbars bounce off the rocks quite often. They both look very stable as they are bright yellow with dark bars. I thought that this was a sign of stress, but they look good?

Any suggestions?

 

[T1KARMANN]

its normal all tigers like to rub themselfs on rocks substrate or other decor