Most of biodiversity is not considered charismatic and from human's perspective it can be indifferent, problematic, harmful, disgusting, or dangerous. Secondary school students' attitudes towards an unloved species and how it relates to their feelings of disgust in the context of a biology course were studied during a citizen science project where Finnish secondary school students surveyed the occurrence of urban rats. Questionnaire data were collected on four scales: attitude towards rats, interest in learning about environment, disgust, and liking biology as a school subject. It was modeled with an item response theory approach by including respondents' age and gender. Higher age correlated with a more positive attitude towards the environment and lower level of disgust. Surprisingly, the students with more positive attitude towards rats also not only had a higher liking biology as a school subject and positive attitude towards the environment, but also a higher level of general disgust. The results suggest that disgust in general is not detrimental in learning and appreciating unloved others as parts of biodiversity. The results also raise questions on how personal attitudes towards the individual species relate to attitudes toward more abstract concept of biodiversity or the environment.