Mum & dad will keep that nest as clean as they need it to be for the greater good of the nest.
Wait till you discover the joy of the poo sack . . . . The runt is often sacrificed for the greater good, & I often wish that was extended into Homo Sapien culture.
They have extremely small brains & most of the folk who self elected themselves to define our natural world have it horribly wrong.
Because you only have to sit transfixed in front of your very own 'nest cam' to discover that we donate £millions to folk who really don't have a clue.