I have seen others use these bottles for bird cages successfully. I think that the one showed differs substantially from the one received. There is no mechanism to afix the bottle to the cage; at least not one that comes with the bottle. If you ave used these before, I am certain you will have better success. There are now bottle cap compatible waterer that will accomplish the goal if you are using the products for birds cheaply and more securely. What do you do to attach these to a cage anyway?