Black Sunflower seeds

[Bill & Jaye]

I just went to a new / different bag of black oiled sunflower seeds and found that the birds are taking a LOT of seeds out and wasting them & not cracking them.  I am wondering if the shells are harder or something like that.  I did not have this problem all winter when I was using seeds from a different source.
Any help / thoughts would be appreciated.

[bronco]

I wonder if they are old - have a look to see if there is any sort of "packaged date" or "best before date" or code that might provide a clue.