These are probaly Scilla and ther short answere is that you don't get rid of them, they are in your garden for ever! let them bulk up and enjoy the flowers as we have to do.

they do tend to be there forever as BA says but you can dig them out or cut the tops of as the foliage emerges. eventually they will fail to thrive.

They are a lovely shade of blue, I'd like lots of them.

Is there a picture with this question?
The most annoying blue bulbs are Muscari ambrosiacum (Grape Hyacinth). I have just dug up and binned a 4 gallon bucket full of them and I reckon I could remove the same number again. I did this last year too and you would not think I had bothered.
M latifolium is not much better either.

Bearing in mind that they are so rampant, I wonder why you don't see them in the wild.

We have seen lots growing as weeds in the olive groves in Spain.