Mental stimulation?

[SoVery]

Can anyone recommend some good toys for mental stimulation? I have a year old purebred Cocker and he has a long run every day but I worry he gets bored in the meantime! He has lots of interaction, only crated overnight, but I hate to think he's bored! He's not showing any bad behaviour, he seems perfectly content, this is just something that I think he should have.

TIA!

Scentwork.

Hide his food around the garden/house and let him search for it.

All dogs love scentwork but spaniels adore it.

Agree with scentwork but my own spaniel also loves learning/training.

Well, specifically, what he LOVES is being asked to do something that he knows how to do and then getting it right. As a result, he's learned a load of, seemingly useless, tricks such as 'fainting' when I shoot him with my fingers or going and fetching my slippers. We throw in more useful behaviours, such as a tight legged heel, that can then be taken out and practised on walks.

We also have a few interactive toys (Nina Ottoson, I think?) that we hide treats in and we/he can play with.

I’m trying to do scent work to keep my springer pup entertained. She is so bad at it! She mostly sits on her food!