Harvesting guano fertilizer from old farm houses - a new business opportunity?

Here's a post with nothing to do with law, and only very little to do with agriculture.  These are photos taken today while I tore down part of the ceiling over our veranda after the supply of bat manure reached critical mass.  The first photo in the series is of one of the fragments of newspaper I found in the ceiling - with a news story dated April 1, 1881.  Hopefully it will be another 130 years before I need to clean the ceiling out again!