* Defining "pleasure" is subjective: What constitutes "pleasure" in a mammal is difficult to assess. We can't directly ask them!
* Observing behavior is complex: We can observe mating behaviors, but it's hard to interpret them definitively. We can't know the internal experience of an animal.
* Evolutionary pressures: Most mating behaviors are driven by evolutionary pressures to reproduce. Even if some mammals experience pleasure, it's likely that reproduction is a primary driver.
However, there's strong evidence that some mammals, including humans, experience pleasure during mating:
* Neurochemical changes: Hormones and neurotransmitters associated with pleasure (like dopamine and oxytocin) are released during mating in many species.
* Prolonged mating: In some species, mating lasts longer than is strictly necessary for reproduction, suggesting pleasure may be involved.
* Social bonding: Mating can strengthen social bonds in many species, which might be linked to pleasure.
In conclusion: While we can't definitively say how many mammals mate for pleasure, it's likely that some do experience pleasure, and that pleasure may play a role in their mating behaviors beyond just reproduction.