Troubleshooting your worm bin

Problem: The bin smells bad

A healthy worm bin should smell like fresh earth — not rotting food. Bad odours almost always have one of three causes:

• Too much food — if scraps are piling up faster than worms can process them, the excess rots anaerobically. Stop feeding for a week, then resume in smaller amounts.
• Wrong foods — meat, dairy, and oily foods create hydrogen sulphide and ammonia. Remove any offending scraps and don't add them again.
• Too wet — a waterlogged bin goes anaerobic. Add dry, shredded cardboard or newspaper and mix it in. Drill extra drainage holes if water pools at the bottom.

Problem: Worms are escaping

Worms leaving the bin signals that conditions inside are unfavourable. Check for:

• pH imbalance — too much citrus, coffee grounds, or fermented food can acidify the bin. Add crushed eggshells or a small amount of garden lime to neutralize.
• Too wet or too dry — bedding should feel like a wrung sponge. Adjust moisture accordingly.
• New bin stress — freshly set-up bins sometimes see worms try to escape in the first 48 hours. Keep the lid open slightly and shine a light on the bin overnight; worms avoid light and will settle in.

Problem: Fruit flies

Fruit flies breed in exposed food scraps. The fix is simple:

• Always bury food scraps under the bedding rather than leaving them on top
• Cover the surface with a layer of damp newspaper or cardboard
• Freeze fruit scraps for 24 hours before adding them — this kills any eggs already present

If an infestation is already established, place a small bowl of apple cider vinegar with a drop of dish soap near the bin — it traps adults. Continue burying food until the population dies out.

Problem: The bin is too dry

Bedding should feel moist throughout. If it's drying out:

• Spritz the surface with water and mix it in
• Cover the top layer with a damp piece of burlap or newspaper to retain moisture
• In dry climates or heated homes, check moisture weekly

Problem: Worms aren't multiplying

If your population seems stagnant after a few months, check the basics:

• Temperature — red wigglers reproduce best between 18–24°C. Below 10°C they slow dramatically; above 30°C they struggle.
• Overfeeding or underfeeding — erratic feeding disrupts the bin environment. Feed consistently in small amounts.
• Protein levels — occasional additions of coffee grounds or small amounts of cornmeal can boost reproduction.

When to start fresh

If the bin has completely gone wrong — severe pest infestation, complete die-off, or extreme contamination — it's sometimes easier to start fresh than to rescue it. Rinse any surviving worms in clean water, set up new bedding, and begin again. It happens to everyone at least once.