Like most other small lizards, blue tail lizards consume a variety of invertebrate and vertebrate prey. The term “blue tail skink” may refer to any of several different species, but keepers most often apply it to five-lined skinks (Plestiodon fasciatus), broad-headed skinks (Plestiodon laticeps), or southeastern five-lined skinks (Plestiodon inexpectatus). However, some keepers may use the name to refer to juvenile Great Plains skinks (Plestiodon obsoletus).
Insects are important prey for blue tail lizards living in the wild, and they usually form the bulk of the diet for pet lizards. Grasshoppers, crickets, roaches, beetles and flies all show up on the menu of these lizards, as do their larval forms. Those who keep several pet lizards may benefit from culturing roaches or crickets at home to save money and for the sake of convenience.
Blue tail lizards also consume spiders and scorpions in the wild, despite their venom-delivering fangs and stingers, respectively. While some keepers may drop a small, captured spider into their lizard’s tank from time to time, it is best to avoid food items that can defend themselves, as most arachnids can. Additionally, the possibility that you may suffer a bite or sting provides ample reason to avoid the practice.
Most lizards, including blue tail lizards, will consume earthworms when possible. Blue tail lizards also consume slugs and small snails as the opportunity presents itself. While both make suitable food items – you must avoid offering snails that are too big for your lizard to handle. Only provide him with snails that are about the size of his eye or smaller. It is also important to ensure snails and slugs are only collected from areas in which pesticides have not been used.
Large blue tail lizards – especially broad-headed skinks -- will not hesitate to devour smaller lizards. Because of the parasite risks associated with offering your pet wild-caught lizards, and the costs associated with purchasing suitable quantities of captive-bred lizards, it is generally inadvisable to feed other lizards to your pet. The fact that blue tail lizards may eat smaller lizards means that it is unwise to house lizards of different sizes together.
Although it is rare for wild blue tail lizards to encounter nestling rodents, many large specimens will eat suitably small mice, when the occasion arises. Care must be taken to avoid providing too many rodents to your lizard, and it is not necessary to offer rodents at all. If you do choose to feed rodents to your lizard, only offer frozen-thawed or pre-killed rodents to avoid causing unnecessary suffering for the feeder rodent.