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Frequently Asked Questions - Black Soldier fly Larvae (Nutrigrubs) FAQ

Frequently Asked Questions - Black Soldier fly Larvae (Nutrigrubs) FAQ


Black Soldier fly Question Quicklinks:

To help you navigate our frequently asked questions on BSFL so you can find your answer more quickly


What are Black Soldier Fly Larvae (Nutrigrubs)?

Black Soldier Fly Larvae (BSFL) are the larval stage of the Hermetia illucens or black soldier fly, they have many names, most of which are brand names for the same insect. BSFL is one of the better staple feeders for any reptile, amphibian, and many other species. BSFL resembles a stereotypical small maggot-like insect and is almost translucent as you can see the substrate that has been ingested by them through their pale skin.


Nutritional Information for Black Soldier Fly Larvae:

  • Moisture 61.2%
  • Protein 17.5%
  • Fat 14%
  • Ash 3.5%
  • Fiber 3%
  • Calcium 9340mg/kg
  • Phosphorous 3560mg/kg


What are the other names for black soldier fly larvae?

"Phoenix Worms®", "CalciWorms®" and "ReptiWorms™"

Phoenix Worms® is a registered trademark of Insect Science Resource LLC. All rights reserved.

CalciWorms® is a registered trademark of Timberline Fisheries. All rights reserved.

ReptiWorms™ is a subsidiary of Animal Specialties Inc. All rights reserved.


Are BSFL good for my pet?

Yes. They are one of the best staple feeders available for insects eating pets. They are soft so easily digested, easily stored, make no noise, do not smell when kept properly and are very nutritious. They are an underused feeder that is likely to become much more popular in the future as more people realize how good of a feeder insect they are.


How do I store my BSFL?

Your black soldier fly larvae will arrive in a small plastic cup along with a substrate that can be made from walnut bedding but also other materials, depending on where you get them. Keep them in the container with their substrate, no need to feed them, no need to gut-load or supplement them either. Some places recommend you keep them in the fridge, but our experience tells us that this is too cold and they are better stored in some kind of wine cooler/beverage chiller. Just be sure to remove any dead ones or you may detect an ammonia smell, this can be gotten rid of by removing dead worms and letting the container air out for a couple of hours to remove some of the humidity from the tub.


How long do BSFL last?

If kept cool they can last up to a couple of weeks, but when kept at room temperature they can start to pupate before then so try and feed them off as quickly as possible. When they start to pupate they will turn dark so always feed the darker ones first.


Will my BSFL turn into flies?

They can, if kept at room temperature they can pupate and turn into flies in a week or two. Kept at cooler temperatures they will take less time but eventually they will all turn.


Can I feed the flies to my pet?

Yes, the flies are nutritious and edible. They can make a change to the usual insects that your pet may eat and some love to catch the "sky raisins". They are able to be safely fed, but bear in mind the lifespan of the black soldier fly is only 5-8 days at most.


Do I have to dust my BSFL?

No. BSFL contain enough calcium and other nutrients to act as a supplement on their own, they do not need dusting nor do they need gut-loading.


Do I have to gut-load my BSFL?

No. As with supplementation there is no need to gut-load your BSFL.


Do BSFL bite?

No. They are soft maggots and cannot bite nor harm your pet.


What happens if my order arrives dead?

Every effort is always taken to ensure that your order arrives alive, we always pack more bugs into our shipments just in case. On the off chance that your order does arrive dead, just send us a photo of the dead bugs in the container they came in and we will send you a replacement or issue you a credit on your account as long as the package has not been left outside to sit for longer than 1 hour.


What if I receive the wrong item?

If you receive the wrong item, please send us a message with your order number, the item you received, and the item you were supposed to receive. We do make mistakes, but we would be happy to send a replacement order.



What if I receive someone else’s order?

This doesn’t happen very often, but there is always a chance we may mix up a packing slip or shipping label. If this happens, just send us the order number of the order you received, and your order number so we can send a replacement order.


If you have any questions that haven't been answered here, go to the page for your product in question and scroll to the customer reviews and post your question there.

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    Reptile Supply - August 30, 2021

    Hi Jeffrey — The best way to prevent black soldier flies from potentially proliferating in your yard is to offer them in a spill-resistant dish and make sure they all get eaten. Freeze any that don’t get eaten to kill them before disposal.

    jeffrey - August 30, 2021

    I’m looking into larvae instead of worms
    I do this outdoors during the warm weather
    I don’t want to release black flies into my yard
    How do you control them?
    Thank you

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