Bug : the mitose for sparrow says doesnt waste any exp when making more sparrows i had 500k exp and clicked on it it reset to 0 on the next tier its a lie it wastes ur exp but it says it doesnt
Mitosis only uses what exp it needs for the upgrade. If you wanted to mitose your sparrow, and you had 750K exp but only needed 500K for the upgrade, you would still have 250K left over to use after mitosis. It won't waste any extra you have, but it doesn't mean it doesn't cost the exp indicated to perform.
It's not like seeds where after a certain point, they are no longer spent when upgrading.