Answers about the observations
Second observation: this is to answer your research question.
Observe the same or a similar animal again (could be a different video) and then note the RELEVANT behavioural units you see every 20 seconds. If the animal is active and you see something at 0, 5, 9, 17 and 20 seconds, then only write down the ones at 0 and 20 seconds: This is your protocol.