Are red wiggler worms a potential invasive species?

A neighbour has red wiggler worms to give away. He uses them in fishing.

Since my compost system is frozen solid for nearly 6 months of the year, I'm considering options. Not a little weenie apartment sized operation either.

The question is, do I need to sterilize the castings to ensure all worms/eggs are dead before applying to pots and gardens?

I'm trying to make the local soil and habitat better. i'd hate to make an idiot play and make everything worse.

*poke*

Potentially, but i admit i don't worry about it too much. They are supposed to die if the soil freezes, but mine have survived in compost piles and my garden under layers of mulch.  You're a zone colder than me, though, with a longer, less lake moderated winter.

Essentially all earthworms are an invasive species anywhere there were ice sheets:

https://canadiangeographic.ca/articles/the-silent-migration-beneath-our-feet/

I've definitely seen birds snacking on my worms.

Just to be upfront, I could be wrong!

I think the 'invasiveness' of red wigglers is dependent on your climate/zone. I have not seen them exist outside of a compost heap or something that is really rich in organic matter. I have heard that red wigglers were widespread when horses were the primary source of transportation due to the abundance of manure but now are essentially 'artificially' preserved by captive breeding. I'm sure there are some that go out into the environment and persist but I have not experienced an invasive bloom of the population. They are considered an epigeic worm that exists in the topmost layer of the soil and don't burrow like other earthworms.

Maybe in more tropical settings with temperatures that they favor they could be a bigger issue? For me, with some freezing winter weather, feel comfortable adding them to my compost pile but that's a personal choice.

Thanks. I'm getting the same range of opinions from other sources -- it seems the bottom line is "we don't know for sure."

I'm not too worried about the actual worms -- I can arrange for the cold to kill them. The egg cocoons are said to be much more hardy. I suppose I could do a controlled test where I freeze the castings thoroughly and then see if young worms magically appear.