The opening has a recycled piece of plastic knit inside to keep it open. The plastic is flexible so it won't break if they decide to sit on top of it. The plastic is cut from plastic food containers that have been fully washed.
Since this is knit it will keep them warm, but also has holes to let the air circulate through. If it gets a little stinky (and I know they do!) just throw it in the washer and dryer and put it right back in their cage when it's clean.
We have tested it on our own two rats. They are medium sized rats and they both fit inside together, although they are very snuggled when they get in together. The opening is 10" in circumference, but can be stretched quite a bit. It is 8" in length. If you want one to fit two rats comfortably check out the medium sized bed.
yarn color will vary depending on what I have. if you want a particular color please let me know.
**UPDATE** I am now making these from t-shirt yarn when I have it. If you prefer not to have t-shirt yarn let me know
convo me with any questions.
Have any questions? Contact the shop owner.