How are insects grown for dog food and cat food?

Insect protein is gaining acceptance in pet food not because it's cheaper or easier to produce, but because the environmental footprint is substantially lower than conventional livestock and the protein quality is genuinely high. Understanding how insects are farmed helps explain both why the nutrient profile is good and what the sustainability case is actually based on.

The two species used at scale in Europe

Two insect species dominate commercial protein production for pet food in Europe: black soldier fly larvae (Hermetia illucens) and yellow mealworm larvae (Tenebrio molitor). Both are raised in controlled indoor facilities and produce protein with similar functional properties, but there are meaningful differences between them.

Black soldier fly larvae have a life cycle of roughly 14 days from egg to harvest at the larval stage, making them the fastest-cycling option. Their fat content is higher than mealworm larvae, and they can be raised on a wide range of organic waste streams including pre-consumer food by-products. Protix, one of the largest European producers, operates a dedicated black soldier fly facility in the Netherlands. [1]

Mealworm larvae have a longer life cycle of around 60 days to full larval development. They require very low light conditions, generate relatively little heat during growth (reducing facility cooling costs), and have been farmed in Europe for over 50 years in the fishing bait and bird feed industries. Ynsect, based in France, operates one of the largest mealworm production facilities in the world. [1]

Both species yield insect meal with a crude protein content significantly higher than raw fresh meat, which contains around 20 to 25% protein by fresh weight. Processed insect meal ranges from around 55 to 70% crude protein depending on the species and processing method. [2]

What insects actually eat

Insect larvae eat organic material that would otherwise go to waste. Mealworm larvae are typically fed on by-products from the grain milling and brewing industries: bran, brewer's grain, and dried vegetable matter. Black soldier fly larvae can process a wider range of substrates including fruit and vegetable waste, spent grain, and other pre-consumer food industry by-products.

This waste stream conversion is the core of the sustainability argument. Instead of raising livestock on arable cropland, insect producers convert the food industry's waste into high-quality protein. A 2017 lifecycle analysis found that black soldier fly larvae production generates approximately 1 kg of CO2 equivalent per kg of dry matter, compared to roughly 10 to 12 kg for beef protein. [3]

The production process: from larva to kibble ingredient

At harvest, the larvae are cleaned, cooked, and sterilised. This process is required by EU regulation and inactivates pathogens. [4] The cooked mass is then dried and milled into insect meal, a stable powder with a long shelf life. The production process also yields two useful by-products:

• Insect oil: extracted during drying, used in animal feed for its fatty acid profile
• Insect frass: the excrement and shed casings from the growing process, which functions as a high-quality organic fertiliser

Why insect protein carries a low allergy risk

Food allergies in dogs are caused by the immune system recognising a protein it has encountered repeatedly and mounting a hypersensitive response. The major canine food allergens (beef, dairy, chicken, lamb) are proteins that appear in most conventional dog food formulas and to which dogs are regularly exposed from an early age. Dogs in Europe have had very little exposure to insect protein over the past decades, meaning the immune system has no established sensitisation to it. [5]

This makes insect protein particularly useful for elimination diets in dogs with suspected food allergies. It's a single novel protein source with a defined amino acid profile and documented low allergenicity.