 To develop , the larvae must be fed both nectar for carbohydrates and pollen for protein . Bumblebees feed nectar to the larvae by chewing a small hole in the brood cell into which they regurgitate nectar . Larvae are fed pollen in one of two ways , depending on the bumblebee species . Pocket @-@ making bumblebees create pockets of pollen at the base of the brood @-@ cell clump from which the larvae feed themselves . Pollen @-@ storing bumblebees keep pollen in separate wax pots and feed it to the larvae . 
