The birds of the air do GOD's bidding. ~ Reference (1 Kings 17:4-6)

God ordered ravens to feed Elijah at the Brook Cherith. The ravens brought found to Elijah day and night. God could have sent angels to deliver food to Elijah, but chose to use mean creatures instead.  

God has control over the mightiest and the smallest creatures, and can use them as He pleases to accomplish His purpose.

The King, Invisible ~ (1 Timothy 1:17)

God is invisible to the human eye, yet He manifests His presence in our lives with His infinite power and character.  Many doubt God’s existence because He is invisible.  Think for a minute how the earth came into existence: the trees; the fish in the sea; the birds in the air; and the tiny ants that move around and work as we all do. Surely, a Supreme Being whose power and wisdom we cannot comprehend created them all.