“I’ve found this transparent worm in my terrarium after two months of setting it up”, writes Thomas about the near-transparent, worm-like creature pictured below. “It’s a closed terrarium and I sometimes open the lid for ventilation because of fog buildup. I’m living in Hong Kong and at the time of discovering this worm, it was winter, with temperatures around 12°C to 20°C. The worm appears to have a black head and is not moving at all. It measures around 1 to 1.5cm in length. Is this worm harmful to my plants? Why does it suddenly appear in my terrarium? The plants I used are all free from pests as they come from nurseries. Thank you.”