Now the squirrels can't move it to hop over. This arrangement is still working, although I hope my boasting now doesn't jinx my luck. There is, finally, a cage feeder filled with black oil sunflowers. Goldfinches and chickadees move easily through the grill, but squirrels are excluded. When they learned to remove the cage lid, they were foiled by a snap I found at the hardware store.
Many food sources exist for squirrels in their natural surroundings.
In my yard they eat acorns, maple seeds and seeds from pine cones. When the pear tree had a bumper crop last summer, the squirrels enjoyed the ripe fruit along with the crows, groundhog, bees and butterflies. They eat seeds from the lilacs, which are also taken by cardinals. In severe winter weather, or very occasionally, I provide heels of bread, leftover peanut butter and jelly sandwiches, and my failed or stale muffins and biscuits. After Halloween, I put our pumpkins on the stone wall out back.