Worms are not needed in the HOTBIN, but don’t be worried if you do find them, red stripy brandling worms are very common in the HOTBIN and aid the breakdown of waste into mature compost.
Bacterial activity largely powers the decomposition of organic waste; however with the presence of worms this may also result in a rich vermicompost being left behind, along with mucus deposits from the worms gut digestate which some studies have shown to be beneficial to soil fertility.
How do worms get into the compost heap?
Worms and worm eggs casts are found in soil or old compost just like slugs and snails and can also be found attached to leaf mould (tiger worms are used to decompose leaves). In the case of the HOTBIN which is a sealed unit, worms are often added during the set-up of the initial base layer if you are using old compost to inoculate the heap with an injection of bacteria.
Can the worms survive the hot temperatures?
No, not in the top most active layer of the heap. Worms and egg casts are unable to survive the high temperatures inside the HOTBIN once it reaches above 35°C.
However to explain further, the heap inside the HOTBIN has distinct temperature zones with a cooler layer at the base where worms can survive. AS heat rises and due to the top layers having the freshest waste typically the temperature increases towards the top of the compost heap. It is common to see an increase in the HOTBIN worm populations in the Spring as the base layer has sufficient food and temperature for worms to sustain breeding through the winter.
Should worms be crawling up the walls of the compost bin?
They are trying to escape and a sign that you HOTBIN is heating up! After setting up your HOTBIN the temperature will start to increase and as this happens the worms will start to look for an escape route. This may involve heading for the cooler base layer and sometimes out through the aeration base plate, or as heat rises they may wriggle up to the top of the bin and get stuck near the lid. What you decide to do with the worms is up to you and your personal views; leave them, place them back in the cooler bottom layer or feed them to the birds.
What are the white thread-like worms?
You may or may not of noticed any, just millimetres in length, these worms are called pot worms (enchytraeids) and will not cause any harm to anything in your HOTBIN. They thrive and multiply in more acidic, wetter conditions which common red worm’s dislike.
Note. They could indicate that there may be excessive moisture in your HOTBIN. To rectify this add more shredded paper/cardboard next time you are adding fresh waste.