Hi
Salt wheels are unfortunately one of those things that pet shops sell but that guineas don't need - in the same way we don't need to lick a mineral block. If their diet is ok they should get everything they need from their food. I've had piggies that had licked them in the past, I used to give them to any pregnant sows just in case, but the others just ignore them!
What my piggies like best is cardboard tubes (either large ones they can run through, or toilet rolls) stuffed full of hay - or a paper bag stuffed full of hay. Pampered Piggies sell toys for pigs too, loofahs and stuff, that mine enjoy
Sophie
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