Like others have said, it all depends on the individual... I have an ornate and a delhezi, both around 12 inches and, apart from the (very) occasional glimpse, all i see of them is either snout or tail poking out from the pvc drain they share. I have AquaFX LED lighting which is dimmer than the original T8s that came with the tank and even when they are set to moonlight or night time mode they dont venture out. Even at feeding time for everyone else they arent interested. I feed them after lights out and once everything is pitch black they come out. If i turn the room lights on I see them feeding but they scurry straight back to their cave. Maybe if i only fed when the lights were on hunger would eventually bring them out? As for aggression, Ive seen none. However I had a 3-4 inch flying fox and a 3-4 inch rocket gar disappear under 'mysterious circumstances' and all blame falls on the ornate. So smaller fish beware! Ive had the ornate for 6-8 months and he has grown from about 4 inches to around 12 and hes really thick. Mine eats mainly massivore/sinking carnivore pellets when lights go out. Although when i first had him he was more active and would eat eathworms, krill, bloodworm, shrimp anything at all really. Both the ornate and the delhezi will eat fish but i have to poke it into their cave. They wont come out to get it. Cool fish though, and the (only?) positive side to hardly ever seeing them, is that once in a blue moon sighting, its a little jaw dropping how much bigger they have gotten from the last time...