Black Soldier Fly grubs bring more birds to the feeder

Blogs • July 6, 2021

Black-capped chickadees, white-breasted nuthatches, woodpeckers and a variety of sparrow breeds. These are just some of the wild birds you’ll find visiting your feeders when you use EnterraGrubs™. 

If you’re a birder, you know feed is important, so what makes this different?

EnterraGrubs™ are made from whole dried Black Soldier Fly (BSF) larvae. It’s a highly sustainable feed because the grubs are fed a 100% plant-based diet made from pre-consumer food waste. The traceable food waste contains fruits, vegetables, and grains that would otherwise end up in the landfill. During a 15-day process, the larvae are raised from eggs to prepupae on a carefully managed blend of feed. They are then dried, packaged as EnterraGrubs™ and delivered to retailers.


Benefits of EnterraGrubs™ for wild birds

EnterraGrubs™ are more than a sustainable choice – they’re a nutritious choice too. Here are just a few of the reasons to choose our grubs for your feeder:

  • Reliably produced in North America
  • BSF grubs have 20 times more calcium than mealworms 
  • BSF grubs have a better calcium to phosphorus ratio, which helps with calcium absorption for strong bones and eggshells.
  • BSF grubs have high-quality protein, helping birds through molting.
  • BSF grubs have a higher fat content and unique fatty acid profile, which is important for birds in the winter months.
  • BSF grubs are more durable than mealworms, so they last longer when left outside in the cold. 
  • Wild birds prefer the taste of BSF grubs to mealworms.

How do we know birds prefer EnterraGrubs™ to mealworms?

In the summer of 2019, we conducted our first preference study in partnership with Armstrong Milling and the Riverwood Conservancy Group. In this study, a larger variety and quantity of birds visited the EnterraGrubs™ station over the mealworm. 

Since then, we’ve been conducting more preference studies in North America and around the world. Recently, we connected with Tom Goldsborough –  an avid birder who lives in Winnipeg, Manitoba, Canada. In December 2020, he set up two identical bird feeders, filling one with EnterraGrubs™ and the other with mealworms. Each feeder was weighed in the morning before being set outside and then again at night. Tom let both feeders rest in a dry area before weighing them at night to ensure the results wouldn’t be skewed by any moisture and to save the feed from being eaten by other animals. 


Wild birds prefer BSF grubs to mealworms

So, what did we find? Tom recently spoke to his study on the BirdSense podcast

“There’s a preference, but it takes time,” Tom said. 

During the first two weeks, the birds stuck to the feed they were familiar with – mealworms. But after some time to test out their new meal, Tom found birds were twice as likely to flock to EnterraGrubs™ as mealworms, and they were consuming it at a faster rate. 

EnterraGrubs™ is not only sustainable, but birds love it too.