Something Mysterious

Last night as we were walking with the kids, Bee and G-man went running along a retaining wall that surrounds the homes in our neighborhood. I try to get the kids to not do this. Usually with many threats and counts, I can get them down. Last night was a little different.



As I said "guys I am not going to even say it. You know what you should be doing.", I heard a loud "crack, crunch."



Followed by Bee saying "I stepped on something mysterious." Yes she used those exact words. Me being one that doesn't like stopping along the way, encouraged them to keep walking. However her pleading of "come see what I stepped on, what is it?" intrigued the whole family. With in a few seconds we were all looking. This is what we found.
Do you know what the mysterious thing is?