Albert Barnes Commentary Leviticus 11:20

"All winged creeping things that go upon all fours are an abomination unto you." — Leviticus 11:20 (ASV)

Rather, “All creeping things which have wings,” etc. The word for creeping things may be regarded as coextensive with our word vermin. It is derived from a verb which signifies not only to creep, but to teem, or bring forth abundantly (Genesis 1:21; Genesis 8:17; Exodus 8:3; Psalms 105:30), and so easily came to denote creatures which are apt to abound, to the annoyance of mankind.