Where does “родничок” come from?

родничок (Russian) comes from Russian родни́к, from Russian род, from Old East Slavic родъ, from Proto-Slavic rǫdъ, from Proto-Balto-Slavic radás, from Proto-Indo-European wréh₂ds — root.

родничок (Russian): spring (water source)

Definitions

spring (water source)

Ancestry of “родничок”, step by step

Step	Language	Word	Meaning
1	Russian	родни́к	spring (water source)
2	Russian	род	generation, birth, origin, stock, family, race;...
3	Old East Slavic	родъ	—
4	Proto-Slavic	rǫdъ	thorny, prickly; curly, locky
5	Proto-Balto-Slavic	radás	birth, genus
6	Proto-Indo-European	wréh₂ds	root

Every word from Proto-Indo-European wréh₂ds →Every word from Proto-Balto-Slavic radás →Every word from Proto-Slavic rǫdъ →