I just put my 2 oscars in their new 90 gallon tank. They seem to love it!!! I just noticed them both picking up some of the river rocks in their mouths and it looks like they are chewing on them.. they then spit them out. Normal behavior?? if so what are they doing???

Oscars will decide how they want their tank to look & if they don't like a rock in one area, they will move it, no matter how many times you keep putting it back. I reckon they are just making themselves at home so nothing to worry about

I gave up a long time ago trying to arrange the gravel in my tank how i want it. Oscars and other cichlids will move the gravel around how they like. I actual like it now where the gravel is uneven and in small heaps in places and dips in others. If a larger rock gets partially buried under gravel i just lift it up to sit on the gravel

So its normal right? I used to have an oscar that every time i would get near the tank he would swim down and pick up gravel with his mouth and trow it at me(lol not literally out of the tank but through the glass ) i thought it was the coolest thing ever. Was that normal? Was he playing? Pissd at me lol?

That is completely normal!