In the wild, reptile nests are often predated, parasitized or scavenged. However, such events under controlled, artificial conditions are rare. In 1996, three clutches of com snake, Elaphe guttata, (43 eggs) were infested by dipteran larvae of the family Phoridae. Of these, 42 eggs were predated and the 43rd egg produced a single fully developed, stillborn embryo. This is the first reported case of snake egg predation by fly larvae. Invertebrates may infest reptile clutches for several reasons. These may include the nutritional value of eggs for developing larvae environmental condition for oviposition (i.e., a warm, moist microclimate). Three techniques are suggested for preventing invertebrate infestations from incubation m aterials. In addition, recommendations on sanitation are provided to reduce its occurrence in captivity. Veterinarians and herpeto-culturists should be aware of the negative effects of such infestations and be knowledgeable on how to minimize or prevent their occurrence.