All winged insects … winged things: both verses deal with flying insects (see also Lev 11.21-23). The Hebrew word in verse 20 appears some seventy times in the Old Testament and is a collective term for “flying creatures,” which includes both insects and birds. In this context, however, it is highly unlikely that birds should suddenly appear in verse 20, and it is recommended that “winged [or, flying] insects” be used in both verses.

Quoted with permission from Bratcher, Robert G. and Hatton, Howard A. A Handbook on Deuteronomy. (UBS Helps for Translators). New York: UBS, 2000. For this and other handbooks for translators see here .