What is an essential factor to monitor in relation to rodent breeding success?

Monitoring temperature and humidity is crucial for rodent breeding success because both factors significantly influence reproduction, growth, and overall health. Rodents are highly sensitive to environmental conditions, and their breeding can be adversely affected if the temperature is too high or too low, or if humidity levels are either too high, leading to discomfort and potential health issues, or too low, which can lead to dehydration and stress.

Maintaining the right temperature range helps regulate metabolic processes and reproductive cycles, while appropriate humidity ensures that the animals remain hydrated and prevents respiratory issues, which can arise in overly dry or humid conditions. Together, these environmental factors create a suitable environment that can lead to optimal breeding outcomes and the survival of the young.

The other choices, like temperature only or light exposure, do not encompass all the critical elements that impact breeding success as effectively as the combination of temperature and humidity does. Complex diets contribute to overall animal health but are not as directly foundational to breeding success as the right environmental conditions.