Lars Lewejohann (Copyright: Kopf&Kragen)   Prof. Dr. Lars Lewejohann

Freie Universität Berlin

Institute of Animal Welfare, Animal Behavior
and Laboratory Animal Science 

Königsweg 67
14163 Berlin

E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Head of Unit

Laboratory Animal Science

German Federal Institute for Risk Assessment (BfR)

Diedersdorfer Weg 1
12277 Berlin

Lars Lewejohann (*1970 in Muenster) studied Biology and Philosophy at the University of Muenster and finished his diploma thesis in 1999. Subject of his diploma thesis was the evaluation of housing conditions of laboratory mice from an animals' point of view using preference tests. In brief: If mice have the choice, they prefer enriched housing conditions and will even work (pressing a lever up to 16 times per entry) for the access to a more entertaining housing system.
In his PhD-project "Behavioral Phenotyping of Mice: Methods, Evaluation, and Appliance" he investigated BC1-RNA knockout mice by means of a battery of behavioral tests. Tests were carried out with different knockout lines in different laboratories. The combined results indicate that although BC1 RNA does not code any protein, it seems to be involved in the modulation of explorative behavior.
In order to automate data acquisition, Lars programmed a tracking software using digital image processing techniques (for details on animal tracking, see "Digital Image Processing in Behavioral Sciences"). From 2004 to 2013 he worked at the Department of Behavioural Biology in Muenster as a researcher continuing his work with transgenic mice. From 2006 to 2010 Lars also was the managing director of the Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience (OCC), an association for research and education spanning different faculties of the University of Muenster focusing on behavioral neuroscience. From May 2013 to March 2016 he was employed as an interim professor at the University of Osnabrueck acting as the head of the Department for Behavioral Biology. From September 2016 to March 2017 Lars Lewejohann worked as an interim professor at the University of Goettingen. Starting April 2017 Lars Lewejohann is professor for animal welfare and refinement at the Freie Universität Berlin and the Head of Unit "Laboratory Animal Science" at the Federal Institute for Risk Assessment (BfR), Berlin.
In his current research he focuses on the individual differences, the interplay of cognition and emotion, and the animals' point of view with regard to better housing conditions and experimental designs.

Editorial boards
Laboratory Animals


Publications (see entry on Google scholar for metrics)

  • Kritzler, M; Lewejohann, L; Krüger, A (2007): Analysing Movement and Behavioural Patterns of Laboratory Mice in a Semi Natural Environment Based on Data collected via RFID-Technology. In: Gottfried, B (ed.): Workshop on Behaviour Monitoring and Interpretation. Osnabrück.

  • Böckels, C; Lewejohann, L; Sachser, N (2002): Applying elo-rating to assess dominance hierarchiy in male mice. Zoology 105, Supplement V (DZG 95.1): 3.

  • Lewejohann, L; Prior, H; Brosius, J; Sachser, N; Skryabin, BV (2002): Behavioural phenotyping of mice lacking BC1, a non-protein coding gene. Zoology 105, Supplement V (DZG 95.1): 3.

  • Lewejohann, L (2001): Was für ein Haus will die Maus? Rodentia 1: 73-75.

  • Lewejohann, L; Edich, I; Sachser, N (2001): Rhythm of activity in closely related inbred strains of mice. Contributions to the XXVII International Ethological Conference, Tübingen, Advances in Ethology 36. Supplements to Ethology: 204.

  • Lewejohann, L; Edich, I; Sachser, N (2001): Circadian rhythm of three closely related inbred strains of mice differing in aggressive behaviour. Zoology 104, Supplement IV (DZG 94.1): 7.

  • Lewejohann, L; Sachser, N (2000): Evaluation of different housing conditions for male laboratory mice. Zoology 103, Supplement III (DZG 93.1): 31.

  • Lewejohann, L; Sachser, N (2000): Präferenztests zur Beurteilung unterschiedlicher Haltungsbedingungen von männlichen Labormäusen. In: Aktuelle Arbeiten zur artgemäßen Tierhaltung 1999. KTBL Schrift 391. Darmstadt: 170-177.

  • Lewejohann, L; Wistuba, J (1999): Mimicry, disappearing acts and imposters. Reptilia (GB) 8: 70-75.

  • Lewejohann, L; Wistuba, J (1997): Guck mal wer da rasselt - 'Geräuschmimikry' bei Schlangen. Reptilia 6: 28-29.

  • Lewejohann, L; Wistuba, J (1997): Mimikry - Tarnkappen und Hochstapler. Reptilia 6: 16-21.


Responsible for the content of this website:

Prof. Dr. Lars Lewejohann

Königsweg 67
14163 Berlin

This email address is being protected from spambots. You need JavaScript enabled to view it.


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End of September 2018 our application for the cluster of excellence Science of Intelligence got selected for funding within the German excellence funding program!

Understanding intelligence is one of the great scientic challenges of our time. Yet in spite of extensive research efforts spanning many scientific disciplines, our understanding of intelligence remains fragmented and incomplete. The Cluster of Excellence Science of Intelligence (SCIoI) aims to identify the principles of intelligence to fundamentally advance our understanding of intelligence as a whole – be it human, animal, individual, collective or artificial.

SCIoI will bring together researchers from different disciplines, such as robotics, artificial intelligence, neuroscience, philosophy, psychology, biology and human development. This allows to study, for example, how birds, mice and humans solve the same problems, such as mechanical puzzles. The obtained insights will then be transferred to artificial systems – robots or computer programs –, which are given the same challenges. This “synthetic approach” has three central advantages. Firstly, it forces researchers to check whether theories developed for biological intelligence are correct and useful. Secondly, it stimulates new hypotheses for the study of biological intelligence, because the inner workings of artificial systems can be analyzed with much greater detail than living organisms. Thirdly, it fosters a transfer of the obtained insights into technical applications. The approach of studying the same problems in a variety of different systems – animals, humans, robots and swarms – serves the central aim of the Cluster of Excellence Science of Intelligence: The discovery of general principles of intelligence.

If you want to learn more about the work we are doing within the next seven years, check out the Science of Intelligence Website.

Cognitive Bias

Information processing is known to be strongly biased by emotional states. In humans, depressed or anxious individuals are known to have lowered expectation regarding positive events and tend to interpret ambiguous stimuli more negatively. Cognitive bias, the altered information processing resulting from the background emotional state of an individual, has been suggested as a promising new indicator of animal emotion. Animals in a putatively negative emotional state are more likely to judge an ambiguous stimulus as if it predicts a negative event, than those in a "optimistic" emotional state. We established a paradigm to test cognitive bias in mice by training them to associate specific alleys of a maze with either a positive reward or a negative stimulus. Unknown alleys were investigated according to their relative location, i.e., their proximity to the positive or the negative alley. This new paradigm allows to rate individual animals as "optimistic" or "pessimistic" according to their latency to explore an ambiguous alley that is located in the middle between a positive and a negative alley.

In addition, we also tested emotion-like states in honey bees by applying an olfactory learning paradigm using two odorants and blends of these odorants as the ambiguous stimuli. One of the most common bee plaques is theVarroa mite often treated by exposing the bee hive to evaporated formic acid. Shaking the honey bees prior to the test led to a pessimistic judgment while exposure to formic acid did not significantly change the response to the ambiguous stimuli. Hence, there is no evidence that the treatment against detrimental effects on cognitive bias in honey bees.

Here is a detailed instruction for building a bee olfactory conditioning apparatus.


In addition we currently investigate cognitive bias in humans. Please follow this link to participate in our online version of the cognitive bias test.


Selected publications