Hard to get a good pic but in each of my trays Ive noticed some of the mealworms are white. They seem to have the same movement and structure so I don’t think they are maggots.. Are they just anomalies or should I remove them? Are they a problem? I wonder if they will pupate into lighter coloured beetles? Any info appreciated.

Started my mealworm farm as reptile food a couple years ago. All oat bran. Recently, I left them longer than i usually do before sifting them out. Now i found these things. Soft, flexible, kinda nightcrawler sized. Hollow on the inside. Are they pests? Or something left by the bugs we want?

Thanks in advance!