My lilies did the same thing this spring and I suspect a bit of underground mole activity encouraged multiple bulblets to form. Dig and remove new shoots now as they will crowd out the mother bulb and interfere with the production of the large lily blooms you may be expecting. I use a hand spade to get in between the mother bulb and the green shoots of the new bulblets and just dig them roots and all out of the soil. Do this on a cloudy day and replant immediately in a different area and the new starts will grow all summer. Don't expect blooms from the small young plants. They need a few years to buildup reserves in the bulb before they can pump out the blooms. Keep growing, Marianne Binetti