Which preposition to use with nibblings

of Occurrences 2%

I may mention, for example, that this story has been written at one sitting and without interruption, except for the nibbling of some chocolate, by its means.

at Occurrences 1%

Put down some of these 'ere Pastellers to do a mouse a nibbling at a candle, or a battle in the Soudang, or a rat snifin' at a smashed hegg, and you'd soon see they was no good!

Which preposition to use with  nibblings