well after asuming our sheep skin numnhas were at fault we soon realised that it was infact the spillers competition mix was infected with mite, when we put our last 4 bags put into the bins the problem soon came clear. Have to say we contacted spillers who took info on batch numbers ect and we spoke to our saddlery where we purchased the feed from. They were pretty shocked to say the least as they had never had any problem with mites in spillers feed and thought possibly that they maybe had a cross contamination as had a few batches of mite infected feed from a different supplier which they returned immediately, and treated there feed store accordingly,though did note that it wasn't near the spillers mix. Well spillers got back to me yesterday they tested the retained sample of the batch number we provided and actually found it to be infected with mite, so They issued a full refund for the full 10 Bags we purchased even though we had used 6 bags. They said they always test there raw materials for mite before they enter the mill, however the mite eggs are not detectable, and although harmless if in the correct environment they can hatch and breed, so our storage in the house with the heating on at times, must of been ideal for the mite to breed. They said if buying feed in future in the summer or autumn months just to buy it as we use it and store in a cool dry place and we would not have an issue with mites and offered full appology. Spillers horse and pony cubes are on offer at min and works out 13.50ish for 3 bags so the refund they issued will purchse 12 bags, and we have storage in feed bins to take it all this time as we have them on alfa oil as there main feed with a cool feed to add bulk and ad lib haylge and there staying level headed while stabled and in top condition at little cost.