I know that song. My mother is from VA and she used to sing it to me when I was a baby.

Old mister rat took a notion for a wife
To my rat trap a bottom itchy kaimbo
He jumped on his horse and he rode for his life
To my rat trap a bottom itchy kaimbo
Kayro Kayro Give it to flayro
Flayro Flayro Flayro
Anywinkieflemondoodleyellowbug
To my rat trap a bottom itchy kaimbo

He took miss mousie upon his knee
To my rat trap a bottom itchy kaimbo
He said "miss mousie will you marry me"
To my rat trap a bottom itchy kaimbo
Kayro Kayro give it to flayro
flayro flayro flayro
Anywinkieflemondoodleyellowbug
To my rat trap a bottom itchy kaimbo