Four Worm Reproduction Experiment Wrap-up

One of the original four Red Worms added to this bin

Well folks, I decided it was finally time to pull the plug on my Four Worm Reproduction Experiment. I know I’ve really let things slide on the update front, so hopefully the final wrap-up will provide some closure for those of you who have been following along, and are keenly interested to learn how it went.

As a bit of a recap, I started this experiment (I use the term very lightly) back on December 12, 2008 (so about 5 1/2 months ago). I was curious to see how quickly Red Worms can reproduce, and specifically how quickly four adult worms could produce a thriving population of worms.

I should say right off the bat that conditions were FAR from ideal in the bin. The worms had to deal with really dry conditions for much of the experiment given the fact that I was using a flow-through (stackable) worm bin and was quite forgetful when it came to keeping everything nice and wet – especially early on.

In order to limit the amount of disturbance to the system, I decided not to do counts during the experiment – aside from the time involved, I felt that this would potentially have a negative impact on the worms. Those of you who are curious about the population size will be pleased to learn that I did in fact take the time to count the worms yesterday. It took awhile, and I have little doubt that I missed some smaller worms, but all in all I think it is a pretty good estimate of the population.
I separated worms into two categories only – adults and juveniles (as dictated by the presence/absence of a clitellum). From what I could tell, there were FAR more juveniles than adults. Here are the numbers:

Adults: 12
Juveniles: 94

So a total of 106 worms – or an approximately 25 fold increase in population size! I can only imagine how many more worms there would have been if I’d provided ideal conditions.

I didn’t bother to count cocoons, but did see a fair number while I was picking out worms.

As for the four original worms I put in the system, I think they all survived, but there was really only one worm I could say without a shadow of a doubt was one of them (since it was much larger than the rest of the worms in the bin).

All in all (despite the lack of attention), I’d say it was a pretty interesting experiment. I would certainly like to try it again, but next time I’d likely use an enclosed plastic bin and would be more diligent with adding food etc. I also would like to try putting Red Worms and European Nightcrawlers head to head (each in their own bin) in a reproduction challenge to see how they compare.

Here are all the posts (in order of appearance) from the experiment in case you want a more thorough recap:
Four Worm Reproduction Experiment (December 12, 2007)
Four Worm Experiment Update (December 27, 2007)
4 Worm Update – First Cocoon! (January 2, 2008)
Four Worm Update (March 25, 2008)
Mating Red Worms (April 8, 2008)
Fungus Gnat Invasion (April 23, 2008)

[tags]worm composting, vermicomposting, cocoons, worm reproduction, worm eggs, worm bin, breeding worms, worm farming, experiments[/tags]

**For Even More Worm Fun, Sign Up for the RWC E-mail List!**
Previous Post

5 lbs of Red Worms – WOW!

Next Post

Stacy From Missoula MT?


  1. I knew it had to end sometime. Sounds like your’s did better than mine have been doing. Two months ago mine were only up a couple worms ( They has also been suffering some neglect, although they are now in buckets like the rest of my worm bins. I do think I’ll let mine contine, although I’ve actually lost track of which bin the one was, I know which ones were the boys, so will continue to monitor them over the next months.
    Let us know if/when you run another one.


    • Bentley
    • June 2, 2008

    Hey Allen,
    Good to hear from you!
    I will definitely keep everyone posted on the various other experiments I’m hoping to get started.


    • Kyle
    • December 15, 2010

    Inspiring. I have set up a couple of 4 worm bins myself, and am hoping for similar results. From everything I can gather a mature worm can produce an egg sac every 7 days, and reach sexual maturity in 60-90 days. The two main variables I would like some data on are:
    1) time it takes a cocoon to hatch?
    2) number of worms in cocoon?
    I have read cocoons can hatch 3-30 baby worms, and assume healthier worms in ideal conditions will hatch more.
    In addition I have set up a 10 cocoon bin.
    Thanks for all the great info.

    • tal
    • February 28, 2012

    hello Bentley,
    i think that the Result you got (if you could reproduce it) shows that the saying that the worms double in amount every two months is not correct entirely, i thinks that there is an exponential growth rate that is influenced by space, food , temp , wet/dry conditions and worm population size.

    i think that if you would take 4 containers (1 with 4 worms, 1 with 8 worms , 1 with 16 worms, 1 with 32 worms)
    and put in them the same food type and amount , same temp, same wep conditions and same space, you would probably see that after 2 mounths the worm amount increased in that containers will be diffrent from container to container and probably not 2 times the amount you started with.

    what can you learn from this ….
    1. see the effect of worm population and space on the growth rate.
    2. this way you could find the max number of worms (or Weight) that will give you the best reproduction rate.

    • Bentley
    • February 28, 2012

    Hi Tal,
    Definitely lots of factors to consider, and I totally agree that this will obviously depend on how many worms you are starting with. I’m sure with an overcrowded (“maxed out”) system – if anything, you might end up LOSING worms, let alone seeing a doubling or exponential growth. This only makes it all the more ridiculous to come up with these guidelines (doubling in 60, 90 or whatever number of days).

    Would love to do a more extensive study – but it may be beyond my current means (in terms of available time and space).

    • Casey Wilder
    • January 2, 2013

    Hey Bentley!

    I know this is an older thread, but I just read through all of it for the first time! Very inspiring!! Your adult population tripled in that time and it looks like you were getting ready for a juvenile outbreak! Love the content!


    • gigih
    • November 25, 2013

    I am from Indonesia and this is very interesting. I have raised lumbricus rubellus and they are not having high reproduction rate than that peryonix that I easily get from my garden. However; the worm farmer community in my city always telling me that l. rubellus will double 4 times in a month. But I didn’t see any proof of it. We are using worms not for casting but for fish food. So I prefer to choose the best reproduction rate of any worms.

    I want to ask questions to you:

    1. Which kind of worms have the highest reproduction rate?
    2. Have you ever had experience with worms that live far below the ground? not epiegeic if I am not mistaken the spelling.
    3. What is great diets to make them grow faster and mate frequently?
    4. I am really interested with red wigglers, does their close siblings eisenia hortensis also have the same growth and reproduction rate?

    thanks a lot

Leave a Reply

Your email address will not be published.

Get Your Free Vermicomposting Guide!

* Join the Red Worm Composting E-Mail List Today *