How did Montmorency ‘contribute’ to the packing?

Explanation

The packing escapade was already a messy job and Montmorency’s contribution made it even more tiresome. He did his level best to be a “perfect nuisance”. He came and sat down on things, just when they were wanted to be packed. He put his leg into the jam and worried the teaspoons. He also pretended that the lemons were rats. So he got into the hamper and killed three of them before Harris could land him with the frying- pan.