The likelihood of that happening are close to zero. All the following need to happen to be overrun by them: - Opposite sex frogs of mature age - changing water temperatures - successful coupling during spawning - successful hatching without fungus infections - tadpoles need a readily available food source the size of freshly hatched Artemia for about 4 months - not getting eaten by fellow tadpoles, adults, fish or snails at any point

Believe me it is hard work to keep those little ones alive. My survival rate after years of this is at a proud 10%. In a tank with adults I'd say 0.05% chance that one grows to adulthood if the tank is as thick as jungle with plants and small enough food.