I’ve witnessed a house wren puncturing the eggs of a Carolina Chickedee, then toss them out of the box. The House Sparrow is the worst, I’ve seen them: smash bluebird eggs, kill baby bluebirds, kick out the adults then start building a nest on top of baby bluebirds, toss out live babies... it’s horrible :-(
You can bet, when March comes around and the birds begin their rituals, I’m watching very closely!