The female lays from three to four eggs with bluish green spots. The scarlet tanager is a close relative of the western tanager. It makes its home in mature deciduous or coniferous forests. It can sometimes be found living in areas near a city or town that has many large shade trees. Once the mating season has passed in late summer, the male molts and his new feathers are less bright and look more like those of the female.
Insects are the main diet of the scarlet tanager, but it also feeds on fruits and berries.
The scarlet tanager moves slowly when hunting and picks caterpillars and other insects that are feeding on the leaves. It has excellent vision and locates moths on the bark of trees that are nearly impossible for humans to spot.