have any of you guys experienced this before? it was my mom who first told me my green was making low, rumbling, roars! i didnt take her seriously at first but just last saturday, i passed by the tank and i noticed my aro giving me a good stare and an intimidating stance, it expanded its lower jaw pouch and for the first time i heard him give a low rumbling roar! it was quite loud (considering he was in the tank and in water) i thought it was the filter motor but the sound was following my green wherever it swam in the tank! can anyone tell me anything about this? i've read a lot about aros but never anything about them making sounds. 
