Looks like millet... (sorghum is a type of millet).
As above, I suspect that it came from a feeder... although... some people put out the entire seedhead, and other people plant millet as an ornamental.
Could have been carried by a squirrel.
The birds may be waiting for the seed to mature...
I planted millet at my house this summer, and it isn't being eaten by the birds yet either... but.. the seed isn't quite mature either...
I may attempt picking and cooking...
Supposed to be a superfood... As well as something able to grow in the dry sand w/o dumping a ton of water on it.
https://modernfarmer.com/2022/...