Where does “Муравьёв” come from?

Муравьёв (Russian) comes from Russian мураве́й, from Proto-Slavic morvъ, from Proto-Balto-Slavic *marwís, from Proto-Indo-European morwís — ant.

Ancestry of “Муравьёв”, step by step

StepLanguageWordMeaning
1Russianмураве́йant
2Proto-Slavicmorvъant
3Proto-Balto-Slavic*marwísant
4Proto-Indo-Europeanmorwísant
Every word from Proto-Indo-European morwís →Every word from Proto-Balto-Slavic *marwís →Every word from Proto-Slavic morvъ →