For the cardinal, take a toothpick and cut down to make a “stand” and UV resin it in place right below the hole then you can resin or glue the cardinal on it! And the nest you can shape better and put a small glue spot in the bottom of the birdhouse to make it stay. You can glue the eggs down too.
For the ones with the kinetic sand, I mix clear glue into it then put in how it want it. When it dries it looks like the dirt and doesn’t look shiny like the resin will do. 😊