It's poop. Mystery snails lay round white eggs, and they're bigger than that. Plus they come out of a different spot.
Tanks- 55 gal(in progress)-Common pleco, Angels, lemon and rummynose tetra, blue rams; 29 gal planted- rasboras, corys, otos, clown plec, shrimp; 10 gal- juvenile goldfish; 6 gal planted- betta
Other Pets-Maggie(Tricolor Paint Mare), Lily(Sun Conure), Zoe and Melina(Budgies), Leonardo- Bearded Dragon, Pilot and Phoenix(Golden Retrievers), Beckham(german shepard/akita), Myrtle and Richard(hermit crabs)