Betta Fish: My betta enjoying his cave

I bought a cave for my shrimps, and the only one who uses it is my betta.
(I put real plants in his aquarium and those artificial leaf-beds that stick to the glass. I didnt think he'd also like to rest underground).
Shirimps prefer to hide in the log.
He looks very chill 😂 (his name is Rooler).
Pls ignore the super dirty glas xD