This is a great indication of a healthy worm bin. They are creating the nutrients that you need to grow! You have several choices as what to do with the sprouts. You can try to pull them out early, but you are taking a chance at damaging the young
root system. You can also choose to let them grow larger, but you then need to use more careful efforts not to destroy their formed root systems. When these get larger, you need to dig them out a little bit. Your vermicompost bin is nice and dark, and makes a great sprouting center. I'm not sure that I would use it to sprout my seeds, but I definitely would use the seeds that sprout from my kitchen waste.