Sometimes a living thing stops reacting to a repeated change — a process called habituation. Male bettas flare their fins and gills to warn rival males away. You place a mirror against the tank and the betta reacts. Then you remove the mirror and show it again after one minute. Each time you present the mirror counts as one trial. You repeat trials until the betta stops reacting. The next day you test again to see if the fish remembers. Two distinct patterns emerge: extinction, where the warning fails to work, and habituation, where the fish simply gets used to it.

Animals can also lose a stored response over time. Male bettas flare their fins and gills to warn rival males away — but place a mirror against the tank repeatedly and something changes. You show the mirror, remove it, then show it again after one minute; each presentation counts as one trial. As you repeat trials, the betta stops reacting. The next day you test again to see whether the fish remembers. This reveals two ways animals stop responding: extinction, where the warning fails to work, and habituation, where the fish simply gets used to it.

Habituation is when an animal stops reacting to something because it has seen it many times. Male betta fish flare their fins and gills to warn rival males away. Showing a mirror to a betta over repeated trials reveals that its aggressive behavior diminishes with time as the fish gets used to the unchanging reflection.