Pet owners are sometimes tasked with taking care of the pet’s food. Many species of animals enjoy eating mealworms (Tenebrio molitor). Some birds, lizards, hedgehogs, turtles or other animals love the squirmy live food. Mealworm care is probably the easiest of any feeder insect.
The set up should be a plastic container. It depends upon how many mealworms are kept, but usually a small cat litter box or plastic sweater container will do. Some people like to separate the mealworms, in which case three containers would be necessary. A sieve or strainer with tiny holes will help sift the powdery frass (excrement) when cleaning the mealworms. If allergies are an issue, a paper mask should be worn during sifting. It is very dusty, so whenever possible, sift outdoors.
A lid is not required for mealworms, but a lot of people choose to cover them to keep little fingers or paws out of the container. A screened lid is better than a solid one to avoid condensation on the lid.
There are several stages in the life cycle of the mealworm. They go from eggs, to larvae (also called grubs), to pupae and then beetle. The egg is very tiny and hatches a teeny tiny mealworm that is easily missed. They go through many stages, known as instars, before becoming a full-grown mealworm. Then, they morph in pupae and later an adult beetle. The whole process can take many months, depending on what temperature they are kept.
If using the three-container method, mealworms are kept separate from the pupae, which are separated from the beetles. During the pupal stage, they are extremely vulnerable as they are helpless blobs with a big head and no legs. They can only wiggle about without any way to defend themselves. If there is no other food available, the mealworms and beetles will eat them, causing people to opt for separating them.
Mealworms will hide under cardboard or paper. Egg crates and the cardboard core from a roll of toilet paper or paper towels are the most common accessories for the insects. The mealworms will look for a quiet place to molt into a pupa underneath of the cardboard. Eventually the beetles and mealworms will chew their way through cardboard, so it needs to be replaced every now and then.
Their natural diet is grain, hence the name mealworm. Most people feed them commercial mealworm diet, oatmeal or other cereal. They will eat fresh vegetables or other leftover food. Be careful not to get the colony too damp with food as they like a very dry environment. Stale chips or crackers are good, and gets rid of old food without wasting it.
Most animals prefer for the mealworm stage as a food item. Some animals will eat the beetles though. By refrigerating them, you can stop them from growing and molting. However, the longer they stay cool, the less nutrients are in them for feeding them to pets. Warming them and giving them time to eat before feeding them is advisable. Many people prefer mealworms over crickets because they do not smell and are much easier to rear and keep.