Where does “дятел” come from?

дятел (Russian) comes from Proto-Slavic dętelъ, from Proto-Balto-Slavic delbtelas, from Proto-Indo-European dʰelbʰ-tel-o-s, from Proto-Indo-European dʰelbʰ- — to dig, excavate.

Ancestry of “дятел”, step by step

Step	Language	Word	Meaning
1	Proto-Slavic	dętelъ	woodpecker
2	Proto-Balto-Slavic	delbtelas	—
3	Proto-Indo-European	dʰelbʰ-tel-o-s	—
4	Proto-Indo-European	dʰelbʰ-	to dig, excavate

Every word from Proto-Indo-European dʰelbʰ- →

дятел — Etymology, Origin & Word History | Etymology Explorer