Is my mini crayfish lonely?

Hello,
I’ve had my mini crayfish (Cambarellus patzcuarensis orange) for about 2 months now, and I’ve noticed that he’s been acting weird for a while now.
When I first got him, he was really active; running around the aquarium, climbing every stone and plant etc. Now it seems to me that he looks... sad? If that makes sense. He doesn’t do much, just sits around and moves with his little cute hands. He eats well and seems fine physically.

Is it possible that he’s lonely? Or is my aquarium just too small for him and he’s bored?
Thank you for you help

 

Maybe put some fish in the tank as they can get bored, but he is definitely not lonely, as mini crayfish are often cannabalistic.

 

There are many fish with him in the tank, it’s just that he is the only crayfish inside. I’m not sure if they are suuposed to be in pairs? Or do they just, not care about that?
Thank you

 

You can put another with him and if they turn out to be a pair you'll get babies, these are placid by nature but will squabble when they meet and not unusual to loose a claw if things get rough but dont let that put you off it will grow back, you dont say how big your tank is. Show us a picture of your tank

 

My tank: Aquael Shrimp Smart, 30l. It is about 11,4” x 11,4” 13.8” big. There are 2 fish and 2 mini-frogs inside with him.

 

I can't say if there would be problems with them having a go at the frogs but the one seems to live happily with them