Hello and welcome to the forum. I have freeze dried chicken from Etsy so perhaps we have the same one.
I keep it in the sealed packet it comes in. You could store it in a kilner jar too. I just give it how it comes.
Companies just have to cover themselves in case of any contamination in their factories. I use items from Holland & Barrett for my hamster so it is fine to use. What a lucky hamster to have you make them some cookies.