Both, for the bug to exhibit an external change (its color), there must first be an internal change that triggers the color change (its color). Thus, the internal change facilitates the external change. The predator is an external factor that causes an internal reaction (maybe it's fear) in the bug, that internal reaction then triggers an external factor which is the change in color. Just a personal opinion.
an invasion of a microorganism from the external environment
The hormonal change that triggers the start of menstruation is an increase in estrogen levels in the body.
depolarization
change it.
Internal triggers of change can include personal dissatisfaction, a desire for self-improvement, a shift in values or beliefs, a feeling of being stuck or unfulfilled, or a need for personal growth. These triggers come from within an individual and can motivate them to make changes in their life or behavior.
asthma has many triggers or causes every person diagnosed wit asma has different triggers such as mold cockroaches and even season change you should know your personal triggers so you can be aware of them
The three factors that influence behavioral change are motivation, ability, and triggers. Motivation refers to the desire or willingness to change, ability relates to the individual's capability to make the change, and triggers are cues or prompts that initiate the behavior change. These factors interact to determine the likelihood of successful behavior change.
effector
change in daylight length triggers breeding
despolarization
Positive feedback loop is the process in which a physiological change triggers further change in the same direction. The initial change leads to more of the same change, amplifying the response. An example is the release of oxytocin during childbirth, which stimulates contractions leading to more oxytocin release.