the fantail darter, females prefer males who have already mated and are guarding young eggs, possibly because it would reduce the risk of her eggs being consumed by the male. Specifically, females prefer males with young eggs over old eggs, so caring for smaller broods of older eggs may have little to no net benefit to the male. As a result, smaller clutches may end up being entirely consumed. Filial cannibalism in insects Filial cannibalism can act in a way analogous to brood reduction in birds, in order to reduce competition between offspring for resources and maximize the survival of fully-developed healthy offspring. For example, the burying beetle Nicrophorus vespilloides exhibits partial filial cannibalism. Burying beetles bury the bodies of small vertebrates as a food source for their offspring; for N. vespilloides, eggs are scattered a few centimeters away from the corpse. Once they hatch, the larvae make their way to the corpse to feed while supervised by their parents. Clutch sizes can be much larger than the corpse can support, which researchers suggest is due to eggs being laid as insurance for unexpected mortalities, parents being unable to accurately estimate the food capacity of the corpse, or parents being physically constrained to a minimum clutch size (though studies have shown that parents will vary the size of their clutch based on the amount of food available). At higher densities with insufficient food, larvae may not develop completely, resulting in smaller adults that are less likely to find a mate, as well as limiting the maximum clutch size that can be laid. The parents thus kill part of their brood at the earliest stage to maximize the food available for the others. Filial cannibalism can also serve as a source of energy while simultaneously removing nonviable eggs, such as those that have been parasitized. In the assassin bug Rhinocoris tristis, males are more likely to consume eggs at the periphery of the brood, which are most likely to be parasitized by wasps and are also the easiest for the male to access. Although R. tristis cannot distinguish between parasitized eggs and nonparasitized eggs, their preference for feeding on peripheral eggs may be a general behavior to maximize the chances of feeding on nonviable, parasitized eggs. In addition, it would reduce the number of peripheral eggs available to parasitic wasps, forcing them into an inner egg where guarding males are more