Do these fish eat only vallis

[jonathanj]

iv got 4 leopoldi angels in my tank and noticed them really nipping and eating the tops of my vallis
Are angels noted for eating plants as not really saw them munch any other plant

 

[mort]

I've had angels strip broad leaf plants like amazon swords before but this was when they were breeding. There was a recent thread where someone had really destructive angels though so I don't think it's uncommon.