the version i know is different.

my pigeon house i open wide
to set my pigeons free
they fly and fly and fly and fly
as high as i can see
and when they return to they're merry merry mark
they close their eyes and say "goodnight"
caroo, caroo, caroo, caroo,caroo, caroo, caroo.

my great grandmother sang us to sleep with it, and her mother before he sang it, now I use it to sing my own daughter to sleep. i've never heard it sang any other way.