Reference for Bava Kamma 94:10
אמרי הוא הדין אפילו פירות נמי פטור מדיני אדם והא קמ"ל דאפי' סם המות נמי דלא עבידא דאכלה חייב בדיני שמים
Now, that is so only in the case of deadly poison which is not usually consumed by an animal, but in the case of products that are usually consumed by an animal, there appears to be liability even to the judgment of Man. But why should this be so? [Why not argue:] It should not have eaten them? — I may reply that strictly speaking even in the case of produce there should be exemption from the judgment of Man, and there was a special purpose in enunciating this ruling with reference to deadly poison, namely that even where the article was one not usually consumed by an animal, there will still be liability to the judgment of Heaven. Or if you wish you may say that by the deadly poison mentioned was meant hypericum,<span class="x" onmousemove="('comment',' [St. John's Wort.] ');"><sup>9</sup></span>