The only remedy is to dispose of everything and start over. Canadian Nightcrawlers are earth-dwelling worms which require low temperatures. European are composting worms. They live and breed in the decaying matter such as leaves which accumulate on the top of the soil. Additionally, they are far more temperature tolerant.
Earthworms are extremely easy to keep and raise.
There you will find basic information on their care and breeding. Additional information can be obtained from our Books and Videos . I have salamanders and all earthworms that I have seen advertised are too large for me to feed them. We have numerous customers who feed Red Wigglers to their salamanders. The ones of smaller size seem to work well.