Worms have disappeared from my worm farm?
Worms want to escape from a worm bin
We have had a vibrant earthworm farm for many years which we bought as a start up from a reputable supplier and followed all the procedures and enjoyed a successful worm farm. The structure consists of 4 rectangular bins stacked on top of each other with holes drilled into the bottom of the top 3 to allow filtration to the bottom one. We have always only fed them raw non-acidic kitchen scraps. We put the scraps in the top and the tea and castings filter down to the tap at the bottom where the tea is collected. We've had thousands of worms for years now until recently when we saw them reducing in numbers and now there are barely 6 that I can see. Their position with regard to light and the elements has remained unchanged, the weather is normal and there is nothing obvious that I have noticed that might have caused this. We live in Port Elizabeth in the Eastern Cape. Please advise as to what could possibly have caused this and what remedial steps I should take to get the process going again?