and if you are going to get bat shit from a cave... we must ensure that it has the correct contents.. hang out around their habitat. write down what they eat, what they do, etc. you're basically going to have to become a bat watcher for a day or two to really learn everything you can.. once you know what they eat and what kind of bats they are you can make a pretty good guess as to how much n, p, and k their shit will contain.. from this, we may be able to cook up a similar tea..