The first insects that I bred were mealworms. They are very easy to farm, therefore ideal to begin with. But what are they ? And why would we keep them ?




The Mealworm


What is commonly called the mealworm is not actually a worm but the larval form of the mealworm beetle (scientific name : Tenebrio moliror).

The mealworm beetle is a species of darkling beetle or Tenebrionidae.

The mealworm can measure up to 3cm (1.18″) at the last larval stage. It will then lose its “worm” appearance to become a nymph. I like to say that at this time, it looks like an alien. By the way, a funny experiment to try is to take the nymph by the top of its body and gently squeeze between your fingers, it will twist and turn its abdomen all over the place.

Then, to end its metamorphosis, the nymph transforms into a small black beetle, around 1,5cm (0,59″).

Mealworm life cycle

The mealworm mainly eats cereals, for a long time it was considered to be a devastating creature in bakeries in which it would find refuge. Nowadays, the bakeries’ sanitary conditions greatly limit its presence. It is a cosmopolitan insect and it can often be found in henhouses and other places like that.


Mealworm farming


Mealworms are bred for different reasons :

  • Animal feeding : Reptiles, birds, fish, rodents but other insects as well.
  • Fishing : the larva can be used as bait for luring fish.
  • Scientific observation : mealworm farming is very easy, therefore this can be an opportunity for kids to study an insect’s development in class.
  • But also : human consumption. However, you should never eat the ones than can be found in pet shops, which were not raised for that purpose.


Required equipment :


  • Farming trays : As long as the edges are smooth to prevent the mealworms to climb, you can use anything. I recommand plastic boxes, as they are cheap and available in all sizes. In order to save space, you can easily find drawers that you can pile up, which is ideal to me. Make sure you have at least 2 or 3 trays to separate larvas, nymphs and adults to prevent cannibalism. Now if you really want to keep them all together it is possible, but you will have a lot more individuals if you separate the different stages.

Farming trays mealworm

  • Ventilated lids : You don’t actually have to have these, in theory the larvas and adults will never go out of the farming trays but if you are worried or you want to reassure your family, make sure there is some ventilation to avoid the mold.


  • Substrate : The simplest is flour, but don’t hesitate to add pieces of dry bread, varied seeds, bran, etc… in order to supplement their diet. I recommend flour because, for the sieving, all you have to do is to use a colander and only the worms will be left, which is a great advantage, it is also easy to find and cheap.


  • Mealworms  : Except if you know how to make mealworms appear by magic (and in that case please share your secret with me), you will need some indivuals to start your little farm. You will find them in pet shops or fishing stores, I recommend to begin with at least 100g (about 3,5oz), but the more the merrier.


Farming set-up :


You now have all the required equipment and are ready to start !

So, take a first box and fill the bottom up with flour (a few centimeters), or with the substrate that you will use, and add some pieces of dry bread.

It is time for the release of mealworms, just drop them off into the box and here you go. Welcome to the adventure !


Life cycle :


The mealworm is an insect with complete metamorphosis, because unlike some other insects, the larvas will not look like the adults.

o Eggs incubation : 1 to 4 weeks..

o Mealworm’s development : around 10 weeks.

Mealworm size

o Nymph : 1 to 3 weeks.

Mealworm nymph size

o Adult lifespan : up to 6 months.

Mealworm adult size


Note that the more it’s hot, the faster the cycle will be, and vice versa. However I recommend to keep a room temperature or a little more but not above 30°C (86°F) as it would be too hot.

You need to allow up to 2 months after the farming has been set up to see the first births. At first they will be 2-3mm (0,08-0,12″), so keep your eyes open because they are not necessarily easy to see.


Tips and tricks :


There are a few things you need to know in order to succeed in your mealworm farming.

  • Remember to regularly give them something to drink, especially if it is hot and dry. To do so, very simple, take a fruit/vegetable, cut it into small slices and put them in the farming trays. Make sure you take out what has not been consumed after 1-2 days to prevent mold that can damage your farming.

Mealworm food


  • Separate the development stages to avoid cannibalism. To do that there is nothing simpler, empty the flour out with a colander (above another box of course, it would be unfortunate to find ourselves with the floor full of flour) and then you can easily collect all the nymphs and potentially some carcasses. Put the nymphs in a small container before they transform into beetles.


  • The beetles lay tiny eggs in the substrate, so don’t ever throw it away ! When you see a lot of 2-3mm (0,1″) larvas in the adults box then it is time to make a new box for the adults so that your mealworms have a chance to grow. Otherwise, if you can’t see them, you should put the adults in a new box about once a month.


  • If you go on vacation, don’t worry at all, your mealworms will survive. I once put a box of mealworms in a cupboard and forgot about it for 6 months ! And yet they were still alive. So if you leave for some time, don’t worry, they will make it through as long as you don’t forget to remove the food which is likely to rot before you leave, and give a little kiss to every single one of them.


If this article helped you to understand mealworms better and to farm them, don’t hesitate to follow me on this blog and on social media so that you don’t miss any of my articles. If you have any questions, let me know in the comments and see you next week for a new article !

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