Charak Samhita
सर्पाणामेव विण्मूत्रात् कीटाः स्युः कीटसम्मताः । दूषीविषाः प्राणहरा इति सङ्क्षेपतो मताः ॥१४०॥
॥ Dooshi visha (slowly acting poison)॥ From the feces and urine of snakes themselves, insects arise which are of two kinds- dooshivisha (slowly acting poison) and pranahara ( acutely acting deadly poison).
english translation
sarpANAmeva viNmUtrAt kITAH syuH kITasammatAH । dUSIviSAH prANaharA iti saGkSepato matAH ॥140॥
hk transliteration by Sanscript