Worms have no backbone, legs, or eyes, although their bodies are sensitive to light and temperature. But they do play a useful role. They improve the soil by working decaying vegetation into the earth and aerating it with their tunnels.
The Bible speaks both literally and figuratively of worms. The word worm also refers to a worm-like creature, such as insect larva. For instance, the palmerworm, cankerworm, and caterpillar of (Joel 1:4) are all caterpillars, which is the larval stage of various moths. (The NKJV, however, translates these as various kinds of locusts.) Grub is another word used for worm in various translations (Is. 51:8), (NEB, NASB). (Job 7:5) and other passages, which refer to infestation of worms, probably mean maggots, the larvae of flies. Decaying matter often teems with tiny worm-like maggots.
Some worms, such as tapeworms and pinworms, are parasites which invade the human body. Thus Herod could be described as “eaten by worms” (Acts 12:23).
The common earthworm also appears in the Bible. (Micah 7:17) refers to worms (snakes, NKJV) coming out of their holes. Perhaps it was an earthworm also that God appointed to strike at the root of Jonah’s shade (Jon. 4:7). The psalmist lamented: “I am a worm… and despised” (Ps. 22:6). Job claimed kinship with the lowly worm (Job 17:14). (Isaiah 41:14) uses “you worm Jacob” as a metaphor of weakness. The Jews associated worms and fire with the place reserved for the ungodly dead Isa. 66:24; Mark 9:44,48.