This is the oxalis plant mentioned in one of the responses. The confusion came due to the wording of your question.
yes this little yellow flowered oxalis is a nuisance. the seed pods explode sending 100's of seeds several feet away from the parent plant.

as soon as you see new leaf growth they will need treating. dig out as much as you can. the roots spread quite a long way.

You'll need constant vigilance - they are very difficult to eradicate altogether.