In Leviticus 11:20 it says the Israelites must not eat ‘four-legged’
insects. I was wondering what ‘four’ meant for that passage and if all
insects were considered four-legged literally?

Actually, my English translation says “all flying insects that walk on all
fours are to be detestable to you.” I would take “all fours” to be an
expression generally meaning not walking upright. No one should take this
verse to mean that the Bible is teaching that insects have four rather
than six legs. I would assume that the writer of Leviticus was well aware
that insects have six rather than four legs, but that he is using an idiom
meaning insects which crawl around.

John Oakes, PhD