What constitutes the primary food source for the insectivorous Ruby-crowned Kinglet?

Answer

Small spiders, aphids, scale insects, and tiny caterpillars

The kinglet's diet is almost exclusively insectivorous, focusing on very small arthropods, including spiders, aphids, scale insects, and small caterpillars.

What constitutes the primary food source for the insectivorous Ruby-crowned Kinglet?
birdmigrationKinglet