they r tiny pest snails that sometimes come in plants are pests they can get sucked in to the filter and break it. wash the live plants real well and remove any snails u see, the eggs look like snot on the glass or ornaments, with little dots in it as the babies get bigger, dont let them get out of hand, i thought they were qute till i woke up one day and had thousands......they arent the pet snails you might buy mostly they are just a pain, pluss the shelll is hard and i doubt it would be good for a betta to eat it, could get them sick, when my epidemick bloomed i mystersly had several females die off and i think it was the reason,, they bellys looked funny.....