No to Some Spontaneous Generation
Chazal did seem to believe in some level of spontaneous generation of some creatures, e.g. the earth mouse, perhaps certain water creatures arising in cisterns, and insects found in fruits. See some discussion, and further links in the following Rationalist Judaism post:
One popular example, about common folks and scientists of the past, is rats arising from rotting grain. The Flemish scientist, Jan Baptist van Helmont, wrote about it in the very Pesach-appropriate titled work, "On the Necessity of Leavens in Transformations”.
To quote Pasteur’s quote, when arguing against it:
If a soiled shirt is placed in the opening of a vessel containing grains of wheat, the reaction of the leaven in the shirt with fumes from the wheat will, after approximately twenty-one days, transform the wheat into mice.
I’ve seen this attributed to Aristotle, for instance in this Simple English Wikipedia article about Spontaneous Generation, but I don’t trust Wikipedia, and it isn’t in the regular article, and haven’t yet been able to find it.
Anyway, in a recent daf, Bava Metzia 40, there was a debate whether the rate of decay for stored grain was based on a percentage, or a fixed amount. The Tanna Kamma gave a percentage, while Rabbi Yochanan ben Nuri said:
אָמַר רַבִּי יוֹחָנָן בֶּן נוּרִי: וְכִי מָה אִכְפַּת לָהֶן לָעַכְבָּרִין? וַהֲלֹא אוֹכְלוֹת בֵּין מֵהַרְבֵּה וּבֵין מִקִּמְעָה! אֶלָּא אֵינוֹ יוֹצִיא לוֹ חֶסְרוֹנוֹת אֶלָּא לְכוֹר אֶחָד בִּלְבַד. רַבִּי יְהוּדָה אוֹמֵר: אִם הָיְתָה מִדָּה מְרוּבָּה, אֵינוֹ מוֹצִיא לוֹ חֶסְרוֹנוֹת, מִפְּנֵי שֶׁמּוֹתִירוֹת.
Rabbi Yoḥanan ben Nuri said: And what do the mice care how much produce the bailee is safeguarding? Don’t they eat the same amount whether it is from much produce and whether it is from little produce? Rather, he deducts an amount equal to the standard decrease of just one kor of produce. Rabbi Yehuda says: If the deposit was a large measure, the bailee does not deduct the decrease from it, due to the fact that for different reasons it increases. Therefore, he returns the measure of produce that was deposited with him, because the increase offsets the decrease.
A brayta brought in the gemara records the Sages’ response:
אָמַר רַבִּי יוֹחָנָן בֶּן נוּרִי וְכוּ׳. תַּנְיָא, אָמְרוּ לוֹ לְרַבִּי יוֹחָנָן: הַרְבֵּה אוֹבְדוֹת מֵהֶן, הַרְבֵּה מִתְפַּזְּרוֹת מֵהֶן.
The mishna teaches: Rabbi Yoḥanan ben Nuri said: And what do the mice care how much produce the bailee is safeguarding? It is taught in a baraita that the Sages said to Rabbi Yoḥanan: The reduction is due not only to mice eating the produce. Much of the produce is lost, and much of the produce is scattered.
Rabbi Yochanan ben Nuri clearly understands that the mice are eating the somewhat rotting grain. I could have said that his disputants may maintain a concern of spontaneous generation, so that the decay and transformation should be a percentage. But no, we see from the brayta that the mice are consuming, but other factors are causing the loss of grain.
This doesn’t prove that these Sages didn’t believe in spontaneous generation, at least this very particular form of grain → mice, but it certainly strongly suggests it.