[Ria P]

I would just clutter it up a bit more. Things like cork and log tunnels are very popular with Robos. A 55cm long Trixie bendy bridge to sit under and run across they like as well or hides like a coconut hide or wicker tipee. You can use cardboard for tunnels as well like a tube or a small box with both ends open. That's millet sprays in my foster Robo's tank. The tank is too small which makes it look very cluttered but it's only temporary and gives you an idea what other things you could add.