A mild fall can allow wild rabbits to breed later in the year, leaving shallow nests in lawns into the cooler months. These depressions can be easy to uncover while raking leaves or cutting grass, so check for signs that young rabbits have left before tidying the area.
Rabbit nests are usually shallow, bowl-shaped hollows rather than underground burrows. A mother rabbit may place one beneath a bush or in an open patch of lawn, then cover it with dried grass, leaves and fur. The bedding can make the nest look like an ordinary patch of dead grass.
To assess whether a nest has been abandoned, look for collapsed, cold bedding that is coming apart in the wind, with no movement underneath. For an additional check, place two small twigs in an X over the nest and leave them overnight. If they remain in the same position the next morning, the nest is likely empty.
Once you are sure no young remain, wear garden gloves and lift out the fur, leaves and dried grass. If you are concerned about fleas or mites, use a garden trowel to remove the bedding along with the top layer of soil. Put the material in a sealed bag and dispose of it in the garden waste bin.
To repair the lawn, fill the depression with a mixture of topsoil and sand, press it level with the surrounding grass, and scatter lawn seed over the bare patch.
Sources: Tom's Guide.