Is there any seed that squirrels won’t eat?
Ha ha ha ha ha! Pardon my chuckle. Often gray squirrels will leave plain safflower alone–this is not a guarantee, red squirrels and chipmunks will for sure eat it, but generally gray and fox squirrels will not eat safflower. It needs to be fed by itself, do not mix it with other seeds because then squirrels will kick out the safflower and eat the seeds they like. Cardinals, chickadees, nuthatches, house finches, mourning doves and rose-breasted grosbeaks all eat safflower. Most people find that squirrels generally do not like plain Nyjer. If you mix that with fine sunflower seeds, then the squirrels will eat it, but Nyjer by itself often does not interest a squirrel and is the safest bet for a finch feeder. Otherwise your best bet is investing in a squirrel resistant feeder and mounting it properly.