It's kitten, rathe than chickens, supposedly
It was a music hall recitation making fun of the way the working classes used to pronounce -en as -ing (as they still do in certain parts)
As in:
“Beg your parding, Mrs. Harding,
Is our kitting in your garding,
Eating of a mutting-bone?”
“No, he's gone to Londing"
"How many miles to Londing?
“Eleving? I thought it was only seving.
Heavings! What a long way from home!”