My husband discovered thousands of these worms(?) in a drain at the bottom of our (outside) stairs to the basement and also crawling out of a crack between the outside wall and a concrete pad. It seems to have a hardish shell; I can tell when I crush it. Based on the description of a "drain worm", they seem too long to be that. Can you tell me what this is, how we might have acquired so many of them and how we can get rid of them? My husband is suspecting my gardening or composting hobby is the source but I’ve been doing both for many years and this is the first we’ve experienced these critters. Thanks.
Baltimore County Maryland
These are millipedes and they are harmless to us and beneficial decomposers of organic material. In the spring particularly in wet weather, they are more likely to be seen in great numbers as they try to escape drowning. They are likely helping to break down any debris like rotting leaves in and around that drain at the bottom of the steps. You gardening and composting didn't make this happen. They are naturally there but are usually hidden.
Here is an Extension page that explains more: https://chatham.ces.ncsu.edu/2015/07/millipedes-invading-homes-and-garages/