Do we view an animal's paternity as halachically significant [חוששין לזרע האב], where the young resembles the father's species?: Bechorot 17a
The mating season: Rosh HaShanah 11a
Do pregnant animals mate: Bechorot 8b
Linking external vs internal male genitalia with whether an animal produces eggs or live young: Bechorot 8a
Is it possible for kosher and non-kosher animals, or animals of large species and animals of small species, or beheimot and chayot, to produce young together: Bechorot 7a
Is it possible for different species to produce young together if they normally have different procreative styles or lengths of gestation?: Bechorot 8a
Mating time-of-day, by species, as indicative of when a mother will give birth: Beitzah 7a-b; Bechorot 8a
Do injured female animals accept mating advances from male animals: Bechorot 2b
Spontaneous generation of red worms: Rashi Zevachim 22a "yavchushin"
Creatures that produce live young nurse their young; creatures that lay eggs do not nurse their young: Bechorot 7b
Does the atalef creature [usually translated as "bat"] lay eggs and nurse their young?: Bechorot 7b
When twins are born, does the stronger one emerge first?: Bechorot 18a, 18b
Are single-birth young better than those born as part of a multiple-birth?: Bechorot 18b
Do animals produce better young as the first-born, or as later births?: Bechorot 18b-19a
Miscellaneous
What might cause an animal to have eyes of different sizes: Bechorot 3b
Animals' preference for shady locations in the heat of the day: Eruvin 43b
Maturation of a "Tzavua" into a Bat into an "Arpad" into a "Kimosh" into a "Chuach" into a sheid: Bava Kama 16a
Whether an animal is considered to carry itself, when it is being carried: Shabbat 94a
A mother animal can be made to have mercy on her child, by placing a piece of salt by the wound to remind her of the labor, and rubbing the placenta-juices on the child: Shabbat 128b
Kosher animals might abandon their children and come back; unkosher animals will not return if they abandon them: Shabbat 128b
An animal which survives for eight days is considered viable: Shabbat 135b-136a
Animals are afraid of living creatures, but once someone dies the fear is gone: Shabbat 151b
Animals will be afraid of a human being, until he becomes like an animal to them: Shabbat 151b
Circulation of blood through the body: Rashi Zevachim 25b-26a "Shachat v'achar kach chatach"
