So you just bought some worms from a “big worm” supplier in hopes to start your vermicomposting journey. The package shows up clean and tidy in a nice biodegradable cloth bag with print that says in bold “Red Wigglers”.  The cheerful worm mascot printed on the bag gives you a feeling of reassurance that you made the right choice. You take a look at your bounty to find that it all looks in order. Worms a-wiggling, a little slower than normal but alive and well. Well enough anyway. After a drink and a quick snack they should be back to their original wiggle and waggle. So you lay them into their new home, add some bedding, some greens and leave them for a few days. Little do you know, monsters lurk deep within the dark bedding hiding what truly arrived on your doorstep.

Am I Getting Ripped Off?

The term “Red Wiggler” refers to two closely related species: Eisenia Fetida and Eisenia Andrei. When purchasing these worms from a breeder you should expect to see something like this:  

Unfortunately purchasing red wigglers online does not always get you this. You may notice that a majority of the worms in the new bag look slightly different from each other. Now why is this a big deal? Well different worms serve different purposes. They may all process compost but at different speeds. They also have different habits, food preferences and temperature requirements. So it would really suck for half of your worms to die off spontaneously with you being none the wiser. 

We have less of a problem with what is really being sold, a “red worm mix” , and more with how this product is being marketed to the consumer. With the price of worms growing by the year, you may be spending as much as $50/lb for a sack of worms you didn’t even ask for. And the truth is most worm suppliers are selling a mix even if they say its “pure red wigglers”. Some people never even get a real deal red wiggler in their new sack of worms. It’s misleading to say the least (and a few other words that aren't appropriate to say at most).

Why do suppliers market like this?

From large suppliers to the small ones, the process of sorting worms one at a time when you are dealing with thousands is beyond tedious. Almost a waste of time. For larger suppliers it's not worth the time to sift through hundreds of yards of compost to identify a specific variety of worm. These worm beds, because of their size, are often in open environments that can let in many local wild species of worm which mix in with the current population. In addition to this, breaking down large amounts of compost efficiently requires different species of worms to work through it at all levels of depth. Many of these large operations focus mainly on generating castings to make composting mixes and the worms can be seen as a secondary product. 

The term “Red Wiggler” is a common moniker and is not a regulated term so in essence can extend to other worm species. There is nothing illegal about that. Unless the supplier says 100% eisenia fetida/andrei they can really get away with giving you anything. Suppliers are running a business after all and most are going to do what they can to optimize their profits. If they can sort of “sell” you the truth, is what they do really that wrong?  

When the base consumer buys worms from these large suppliers they are often and unknowingly getting a mix of worms that's maybe only 50% red wiggler, or 75% or 10%. There is no real way to tell unless you count them yourself. Is a mix a bad thing though? Not at all. If your goal is to break down organic material into high quality vermicompost, a mix might do a better job than a red wiggler only pile o’compost. But that isn’t the point. You want to actually get what you paid for. And for those of you looking for the real deal, definitely want to make your purchases from a reputable supplier.         

How to tell the difference between Red Wigglers and a Lookalike? 

If you want to know if you were ripped off, or at the very least are interested to see if any other species are occupying your worm bin, we can do a close visual examination. We are able to tell the differences of these worms by: size, shape, coloring, position of sexual organs and movement. This will be easiest with fully grown worms but may be more difficult with juveniles who are not full grown or sexually developed. It may take a couple months before you start noticing differences with your worms so keep your eyes peeled!

Distinguishing features of a Red Wiggler

Size: A red wiggler is about 4 inches long on average. 

Shape: For their size they are usually thicker at the midpoint of their body relative to other worm species. They also have a very tapered neck when extended. Their clitellum protrudes greatly from their body adding to the thicker appearance. 

Coloring: Red wigglers vary from a dark reddish brown to a light orange yellow color. The clear distinction they have is a yellow tail though some Andrei don’t present this feature. What is clear is the vibrant banding which shows up as yellow or orange along their neck and backside. This banding is flush with the body.  

Location of Sexual Organs: The clitellum is found 26 segments from the head of the worm.

Behavior: These worms are not very squirmy and move more like a serpent and slither rather than moving like an accordion. They move slowly and are more calm when handled.

Common Lookalikes  

European Nightcrawlers (Eisenia Hortensis)

These worms are a close relative and look almost identical down to the banding and tapered neck. These worms may also have a yellowish tail but are oftentimes a little bit darker and more of a dark brown color. They share the same proportions but can be up to 4x the size of a red wiggler. When juveniles it’s almost impossible to tell the difference but at maturity it's a lot more obvious. 

Red Marsh Worm (Lumbricus Rubellus)

These worms are native to the United States and are probably the most common composting worm on the planet. So much so that they are considered invasive in some parts of the world like Asia and the middle east. These worms morphologically resemble the red wiggler and are on average the same length and size but show some striking differences. They can be the same red or orange color but present a more gray tail. They have a more “sausage” shaped head and have more distinct segments that bulge out from the body. These segments are not differentiated by any coloring and are not flush with the body. On close inspection they look like a smaller version of their larger cousin the Canadian nightcrawler including their flatter tail.     

Indian Blue Worm (Perionyx Excavatus)

The blue worm is one of the most common worms to get misidentified as the red wiggler as they share the same function and are roughly the same color and size. Significant feature differences include a purplish/blue hue and a slightly longer skinnier body. These worms also move very differently and prefer to move more like an accordion than slither like a snake. They are also a bit more active and can be often found trying to leave the bin they are assigned to.

The features that give them away the most are their lack of distinct banding along their bodies and their streamlined clitellum that is only 13 segments from their head. This clitellum will usually be a smoky white color and will not bulge even when the worm is pregnant.

Is it even possible to get pure red wigglers? 

For some operations they may have been able to isolate some strains of pure red wigglers and only breed those into their supply of worms. But it's tough to tell who is actually giving you what you want.