I’m not sure about the mites, but if you want to open it up and look at it that should be fine. Ordering hay online can be convenient, but it is harder to be positive the condition. I buy my hay in pretty large quantities, I currently have a large bag I bought from someone who buys hay to sell and for her farm. I then keep the main box/bag in my garage, with it somewhat sealed, whether that be folding the plastic on it shut or clipping the bag. Then about once, probably twice now that I have two bunnies, I take a large container I bought from Target for $7 US to the garage and fill it up and keep it in my+the bunnies room. It’s easier than going to the garage every day. I put one of the bunny beds on top and it functions as a hay bin and chill-out spot. If a little hay gets dried out or something, then it probably just ends up in the discarded hay from the bunnies’ litter boxes. My system works pretty well, and the bunnies can’t get into the hay from the bin, some people buy the oxbow hay that comes in resealable bags, but I don’t need the rabbits getting into the bag.

My read of the situation is the likelihood of getting a dead bird, mouse, snake, etc. is pretty low in hay. It’s not unheard of, but I personally have never gotten anything in my 3 years of constant purchasing. If you want to check, feel free, but I personally never do…. haha. Call it wishful thinking!

In terms of storage, I think the most important basics are 1) low to no sunlight and 2) dry. Hay will get yellow fast if left out in the sun and can get moldy/go bad if exposed to water and no able to dry properly.

I think whether you keep it in the bag/box it came in or a plastic container, either is fine. Rabbit owners tend to access the hay supply daily because you are cleaning litter boxes and topping off/replenishing hay all the time, so air flow will get there.

Personally, I get 10lb of hay and it is shipped in a cardboard box. I always have a “back-up” box that’s simply kept in the back of a clothing closet, so no sun light or exposure to the outside world, but nothing real specific with forcing airflow or anything.

I know that Louie doesn’t use the front of the litter box and only the back, so I put hay in the front and in his hay feeder, for Lola, I’m not sure about her litter habits so I just put some hay in the front and in her hay feeder until I find out how to waste the least for her. Some people keep their hay in a nearby closet because it’s a cool, dark space.

I get a big box (25lbs) online and keep it in my basement storage area as I don’t really have room for it upstairs, it comes in a big plastic bag inside the box which I just semi seal up. I then cram as much as I can in a tupperware storage container that I keep in his room and last me almost a week so I don’t have to go trot down to the storage area everyday. I haven’t had any issues with the tupperware container, it seems to keep it staying fresh if anything.

I haven’t seen mites, a few dead lady bugs is about it, and I took them as a good sign! I did get one batch that was a bit less fresh when the whole covid situation first happened and it also came in an amazon box rather than the brands box, but more recent order was back to good quality. I know there are some local rescues that would sell hay and it would help them with costs, but last I checked they had stopped due to covid. That said if you have a car and can drive out to a farm that’s supposed to be your cheapest option.