The use of remote video traps is a popular method of studying animal behavior in nature. It is an efficient, inexpensive and non-invasive way of obtaining samples from the field. In this study, I built and used video traps to look at activity and fighting behavior in the crayfish Astacus astacus. The aims of the project were to see if the crayfish were more active at night and if there was a relationship between activity and water temperature. I was also interested to see if bigger crayfish fought and won more than smaller crayfish and if light intensity and temperature had an effect on fighting frequency. My results showed that the activity was highest during the night, with a peak at around 11 pm to 1 am. There was a positive relationship between temperature and activity. As for fighting behavior, bigger crayfish did not fight or win more than smaller crayfish. Temperature and light intensity had no significant effect on fighting frequency.