What Scripture says
The passages usually raised come from several places. Some critics say each one is a scientific error. Here they are, as the Bible actually words them:
- Bats among birds. Leviticus 11:13–19 lists birds Israel must not eat, ending with “the stork, the heron of any kind, the hoopoe, and the bat” (Leviticus 11:19, ESV).
- Hares chewing cud. “The hare, because it chews the cud but does not part the hoof, is unclean to you” (Leviticus 11:6). The rock badger is described the same way (Leviticus 11:5).
- Insects on all fours. “All winged insects that go on all fours are detestable to you” (Leviticus 11:20).
- The smallest seed. The mustard seed “is the smallest of all seeds” (Matthew 13:32).
- Pi. A bronze basin in Solomon’s temple was “ten cubits from brim to brim… and a line of thirty cubits measured its circumference” (1 Kings 7:23).
- The moon as a light. God made “the lesser light to rule the night” (Genesis 1:16), though the moon only reflects light.
- Jacob’s sheep. Jacob puts peeled branches in front of breeding animals, and they produce striped and spotted young (Genesis 30:37–43).
- A seed that dies. “Unless a grain of wheat falls into the earth and dies, it remains alone” (John 12:24).
What the evidence says
Context
Each of these is a case of judging an ancient text by modern categories. They need to be taken one at a time, and clearly.
Bats “among the birds”
The Hebrew word is ’oph, which means “flying thing” or “winged creature”. It does not mean “bird” in the modern biological sense. The proof is in the next verse: the same word covers winged insects (Leviticus 11:20, sherets ha’oph, “swarming winged things”). The list groups animals by how they move, not by anatomy. Bats fly, so they belong in the list of flying creatures. The English word “bird” is the translator’s choice, not the Hebrew writer’s claim.
Hares “chewing the cud”
Hares don’t have a multi-chambered stomach like cows. But they do something that looks like chewing cud. They produce soft droppings called cecotropes and eat them straight away, digesting their food a second time to get all the nutrients. They also move their jaws constantly. The Hebrew phrase means “bringing up” food and chewing it again; it describes behaviour an ordinary observer sees, for the purpose of sorting animals into clean and unclean. It isn’t a claim about digestive organs. The rock badger (hyrax) also moves its jaw as if chewing, even when not eating.
Insects “on all fours”
“Going on all fours” is an idiom for creeping along the ground, as opposed to walking upright or flying. The very next verses make an exception for insects “that have jointed legs above their feet, with which to hop on the ground”, such as locusts and grasshoppers (Leviticus 11:21–22). The writer is clearly describing how insects move, not counting their legs.
The mustard seed
Jesus is speaking to farmers in Galilee about the kingdom of God. The black mustard seed was the smallest seed they commonly sowed, and was proverbial for smallness in Jewish teaching. Orchid seeds are smaller, but no one in Galilee planted orchids. Jesus is making a point about small beginnings and great growth, not ranking every seed on earth.
The basin and pi
The figures are round numbers, as measurements usually are in ancient texts. And 1 Kings 7:26 says the basin’s rim was “a handbreadth thick” and shaped “like the brim of a cup”. If the 10 cubits are measured across the outer edge and the 30 cubits around the inner wall below a flared brim, the numbers fit closely.
The moon as a “light”
Calling the moon a light describes what we see: it lights the night. We still say “moonlight”. The text doesn’t say the moon produces its own light.
Jacob’s sheep
The text doesn’t endorse Jacob’s method. In the next chapter, Jacob explains that God showed him in a dream which animals would produce striped and spotted young, and says “God has taken away the livestock of your father and given them to me” (Genesis 31:9–12). The narrative presents the outcome as God’s blessing, not as the effect of the branches.
A seed “dies”
A seed planted in the ground stops being a seed: its outer shell breaks down and it becomes a plant. “Dies” is a vivid, true description of that change, and Jesus uses it as an image of his death and resurrection.
Science
Modern taxonomy, which groups animals by anatomy and descent, began with Carl Linnaeus in the 1700s. The Bible’s categories are practical: what flies, what crawls, what swims, what may be eaten. Different categories aren’t wrong categories. People still call whales “fish” and spiders “bugs” in casual speech without denying biology.
Summary
| Claim | Passage | What’s actually going on |
|---|---|---|
| Bats are birds | Leviticus 11:19 | ’Oph means flying creatures, including insects |
| Hares chew cud | Leviticus 11:6 | They re-eat soft droppings and move their jaws like ruminants |
| Insects have four legs | Leviticus 11:20 | An idiom for creeping; jointed hopping legs are counted separately |
| Mustard is the smallest seed | Matthew 13:32 | The smallest seed Galilean farmers sowed |
| Pi equals 3 | 1 Kings 7:23 | Round numbers; inner and outer measurements |
Where they meet
When the passages are read in their own language and purpose, the supposed errors disappear. The Bible uses everyday categories, just as it uses everyday language about sunrise (2.2).
What’s still open
Not much for these examples. Scholars still discuss the exact identity of some animals in the food-law lists, because several Hebrew names are rare and appear only once or twice. Readers should also be careful the other way: the Bible isn’t a hidden science textbook (see 12.11).
Bottom line
These are mostly category confusions. Hebrew ’oph means “flying things”, not modern “birds”; hares re-eat food in a cud-like way. These are ancient categories, not modern taxonomy. It is rated Debated only because a few rare animal names can’t be identified with certainty; none of the standard examples is a real error.