Mishnah Parah 9:2: If insects or crawling creatures fell into it [the water] and they split open [and released liquid into the water], or if their [the waters'] appearance was changed [because of the insects], they [the waters] are invalid. If [the insect was] a chipushit [a type of black worm], either way [even if no change occurred] it invalidates [the water] because it is like a tube [and invalidates the water like any tube or open vessel containing liquid]. Rabbi Shimon and Rabbi Eliezer ben Ya'akov say: If [what fell in the water was] a dira or kina of the produce [types of insect], they [the waters] are valid because those [insects] contain no liquid.

נָפַל לְתוֹכָהּ שְׁקָצִים וּרְמָשִׂים וְנִתְבַּקְּעוּ, אוֹ שֶׁנִּשְׁתַּנּוּ מַרְאֵיהֶם, פְּסוּלִין. חִפּוּשִׁית, בֵּין כָּךְ וּבֵין כָּךְ פּוֹסֶלֶת, מִפְּנֵי שֶׁהִיא כִשְׁפוֹפֶרֶת. רַבִּי שִׁמְעוֹן וְרַבִּי אֱלִיעֶזֶר בֶּן יַעֲקֹב אוֹמְרִים, הַדִּירָה וְהַכִּנָּה שֶׁבַּתְּבוּאָה כְּשֵׁרִים, מִפְּנֵי שֶׁאֵין בָּהֶם לֵחָה:

Mishnah Parah 9:3: If a domesticated or wild animal drank from them, they [the waters] are invalid. All birds invalidate them [by drinking], except for the dove, for she [only] sucks [and no split leaves her mouth]. None of the rodents invalidate it [by drinking] except for the weasel for she laps it. Rabban Gamliel says: even the snake [invalidates] for it regurgitates. Rabbi Eliezer says: even the mouse [invalidates].

שָׁתָת מֵהֶן בְּהֵמָה אוֹ חַיָּה, פְּסוּלִין. כָּל הָעוֹפוֹת פּוֹסְלִין, חוּץ מִן הַיּוֹנָה, מִפְּנֵי שֶׁהִיא מוֹצֶצֶת. כָּל הַשְּׁרָצִים אֵינָם פּוֹסְלִין, חוּץ מִן הַחֻלְדָּה, מִפְּנֵי שֶׁהִיא מַלֶּקֶת. רַבָּן גַּמְלִיאֵל אוֹמֵר, אַף הַנָּחָשׁ, מִפְּנֵי שֶׁהִיא מְקִיאָה. רַבִּי אֱלִיעֶזֶר אוֹמֵר, אַף הָעַכְבָּר: