After reading this I went out and searched amongst the "river rocks" used for landscaping and drainage around our apartments. After a few minutes I discover a s

After reading this I went out and searched amongst the "river rocks" used for landscaping and drainage around our apartments. After a few minutes I discover a small piece of eroded limestone (6cm x 4cm x 2cm) with an almost circular 5mm hole straight through the middle. So now I have my own "hag stone" and can sleep peacefully...