Chulin 6:2-3

Chulin 6:2

If one slaughtered a bird or a kosher wild animal and it was found to be a treifa, or if one slaughtered it in the name of an idol, as secular food in the Temple, or as a sacrifice outside the Temple, or one that was condemned to be stoned – in all of these cases, Rabbi Meir says that one is obligated to cover the blood (considering it a valid act of slaughter), though the Sages exempt it (considering the slaughter inherently invalid). If one slaughtered a bird or a kosher wild animal and rendered it a neveila, or if he stabbed or tore it, he is exempt from covering the blood (because it was certainly no slaughter).

Chulin 6:3

If a person with congenital deafness, one lacking mental competence or a minor slaughtered while others watched, the blood must be covered (because the slaughter is valid); if they were alone, the blood need not be covered (because the slaughter is invalid). The same is true regarding slaughtering an animal and its offspring on the same day: if they slaughtered one animal while others watched, it is prohibited to slaughter the other animal that day (because the first slaughter was valid). If they were alone, Rabbi Meir permits one to slaughter the other animal (because the first slaughter was invalid), though the Sages prohibit this. They Sages agree that if one did slaughter the second animal, he is not liable to 40 lashes.