you say mice i say mouse

"Why are you limping?" I asked my student as we walked down the hall. 

"A mice bit me," he responded. 

"A what?" I asked. 

"A mice" he replied.

"Wait, did one mouse bite you or more than one?" I ask again. Now let's pause because even as I am having this conversation I am kind of like... huh, a mouse! But for some reason I first focused on a grammar lesson- I know call me crazy. 

"One but it was a baby so the small ones are called a mice." 

"No they aren't, if it's one it is a mouse."

"Nuh uh." 

"Ok let's not keep doing this... you got bit by a mouse? How?" 

"I don't know, it bit my foot. We have mice in my house."

"Did you tell your mom?"

"She said 'why did you let it bite you?'" 

"What did you say to her?"

"I said, I don't know mom the mice just bit me." 

"Are you gonna be able to walk on the field trip today?"

"Oh yeah, it's just a mice bite."