Looks more like one of the Hyacinthoides but which one is most likely to be present and/or thuggish for you, I'll leave up to one of your countrymen :-))

Spanish Bluebell, Hyacinthoides hispanica, or the similar hybrid with our native, H. Non-scripta, Hyacinthoides x massartiana. You probably don't want it. It self seeds like crazy, overwhelms beds and leaves masses of huge floppy leaves behind. Nightmare to eradicate. The hybridization is a threat to wild populations of our native Bluebell.

Thanks, floral.

I didn't think it looked like SB, but was concerned it might be.

That was the thug I was thinking of.

It will be hoicked out tomorrow.

SB is definately persona non grata.

I suggest digging rather than hoiking. It's probably already spawned offsets.

they tend to reach really deep, I dug up some around 20cm/ 8inches deep which had produced a new bulb even 2 inches deeper...

Well they got hoicked out, with a fork.

I'm pretty sure I got the lot.

Considering I only put in one jellybean shaped and sized bulb, 2/3 years ago, that is one hell of a growth rate.

A definate thug.

One gardener’s thug is the prized spring flower of another.

Spanish bluebells bloom reliably in my frost free winter climate — USDA 10B — and spread has been slow but steady over the years.

Ground orchids, bletilla striata, have spread far more aggressively than the Spanish bluebells.

They're extremely hardy. They don't need a mild climate to bloom and spread profusely. On the other hand I'd love Bletilla to even survive.

The Spanish bluebells seem more appreciative of colder winters — they are in no danger of taking over anything in my frost-free garden.

My choices of bulbs are limited by mild winters. Other than daffodils, Dutch iris, freesias, and Spanish bluebells, I’ve had poor luck with anything surviving to bloom a second year even if saying suitable for my climate.

Most probably proximity to the ocean keeps a mild winter area of Southern California even milder than farther inland. We’re rarely — like in decades — with a low temperatue of 40 F.

Nancy, have you tried any of the South African bulbs that don't need winter cold? https://pacifichorticulture.org/articles/bulbs-south-africa/

Floral, thank you for those suggestions!