In George Eliot's novel "Adam Bede," the quote "It's ill guessing what the bats are flying after" reflects the uncertainty and unpredictability of life. Just like bats that flit through the night, often driven by instincts we cannot comprehend, people often engage in actions or pursuits that may seem inscrutable. This suggests that the motives behind certain behaviors can be elusive and difficult to understand.

Through this metaphor, Eliot emphasizes the complexities of human nature and the challenges of interpreting the intentions of others. This notion encourages readers to recognize that understanding someone's motivations is not always straightforward, much like trying to predict the erratic flight patterns of bats. The quote serves as a reminder of the intricacies of life and relationships, underscoring the importance of empathy and patience in our interactions with others.