Secondary schools need to develop students’ digital competence. In Sweden this requirement is included in governing documents for school subjects such as civic and history. However, the governing documents for science education in Sweden lack these requirements. This study aims to explore students’ reasoning about digital information retrieval in biology education. The research question is: How do secondary school students’ reason about filter bubbles and their use of search engines when searching for scientific knowledge online? The study employs mixed methods, including (1) a questionnaire with open-ended and multiple-choice questions, (2) written reflections (3) focus group discussions. Altogether 68 students participated in the data collection. The data collection methods were informed by Ribble's framework for digital citizenship and guided the abductive thematic data analysis. Theme 1: search results and science concepts. Students’ responses indicate a belief that search results are primarily influenced by the keywords used and the search history. Students argued that more serious, credible, and precise search results can be obtained if one uses correctly spelled keywords, appropriate science concepts and synonyms. Theme 2: filter bubbles and information overload. Students demonstrated a low level of awareness about how filter bubbles can influence search results and what consequences this may have for social life; rather than problematizing filter bubbles. These preliminary results indicate that the participating students demonstrate insufficient digital competence and under-developed online search practices when searching for biology-related knowledge online. More research is needed on how science teachers can help students develop the skills and attitudes they need to engage critically and constructively with the ever-increasing amount of science-related information online.