Not really true. I have a bunch of hiding spots for my bichirs but I can still see all of them all the time. They're always out and about especially when they're hungry. The only bichir that hid most of the time was my second ornate. It hid most of the day time when it was under 8" but now that it is bigger it's out all the time. Also the trick is to have the hiding spot situated in such a way that the bichir can feel safe and hide under them but you can actually still see them. I use african driftwood, a few flower pots, and fake plants as hiding spots and tank deco.