This is the 8344th most frequent Russian word.
мишей
"Мишей" is the genitive plural form of "мышь," meaning "mice" in English.
'Мише́й', a form of 'ми́ши', plural of 'мышь'. Used here as the object of sight.
В комнате я видел множество ми́шей.
In the room, I saw many mice.
'Мише́й', referring to mice. Genitive plural of 'мышь', in the context of scientific observation.
Мы изучали поведение ми́шей в лаборатории.
We studied the behavior of mice in the laboratory.
'Мише́й' used as the object of the cats' hunting activity, plural.