In 1967, I saw a flying/floating brown sphere.

On an afternoon in 1967, my brother, two cousins, and I were playing in our grandmother's backyard.  We were walking up the side of a steep hill when a small brownish sphere about the size of a ping pong ball started flying around us.  It floated/flew around each of our heads a few minutes while we tried to figure out what it was.
I looked up to see if anyone was in the tree above us because I thought somebody was pulling a prank on us.  The leaves had fallen off the tree so the branches were mostly bare. I saw no one in the tree.
I am not sure why we all just stood still while the sphere flew/floated around us. I remember being very curious but I didn't try to touch or grab it.
It was opaque and a medium to darkish brown.  It made no sound.  There were no lights or markings on it.  There were no windows, either.
Eventually, we decided to run and tell my dad and uncle about it.  The sphere stayed with us for a little bit while we ran up the hill to our grandmother's house.
My dad couldn't find anything out of the normal when he checked around the back of the house.
Occasionally, my cousins, brother and I talked about it over the years but it's been decades since the last time the incident was mentioned.
I'm now a retired Deputy Sheriff.  I have never seen the sphere, again.  Nor have I ever heard of anything quite like our experience.
Witness indicates that the date of the sighting is approximate.  PD