Thanks for the link Dollyanna
I happened to buy some forage from the ebay site (below) last night, I think they're the same as Nature's Grub as they are also based in Fakenham...
https://www.ebay.co.uk/str/norfolkfeeds
Could be, the photos look the same but they have some different mixes, maybe because they are aiming it at the pet market more on ebay.