I have always been a mouse. I don't haggle at yard sales. I apologize when other people bump into me. I squirm when my husband argues with a salesperson, even if he's right.

For the most part, my meekness has served me well. I succeeded in school by trying always to please my teachers and I thrived in the workplace by adeptly avoiding conflicts with my co-workers.

Things changed, however, when this mouse became a mother. Something about being responsible for innocent, defenseless creatures makes me more like a Mama Bear. As a new mother years ago, I was surprised to find myself suddenly approaching strangers with a nervy smile and saying things like, “Would you mind not smoking here? My baby's lungs are pink.”

The mouse in me was aghast. She squealed with embarrassment the day I marched up to a rowdy group of teenagers and admonished them to stop using foul language in front of my children. She covered her face with timid pink paws as the Mama Bear in me scolded a middle-aged man who had cut me off in a parking lot.

“Watch where you're going! There are babies in this car!”

It has been my experience, though, that people tend to respect maternal instincts. The foul-mouthed teenagers may have snickered a bit, but they stopped cursing. The careless driver apologized profusely and left in a hurry. Most seem to know that it's unwise to aggravate a Mama Bear with her cubs. Like cautious campers, they back off slowly, avoiding a direct confrontation.

One of my most memorable Mama Bear moments took place a few years ago when my then 5-year-old daughter Kateri had to be hospitalized overnight due to dehydration from a stomach virus.

Upon our arrival, a nurse told me that Juliette, my breast-fed baby, would not be permitted to spend the night with us in Kateri's room. She left me sitting on the bed, facing the impossible dilemma of choosing which of my children to abandon for the night. I looked at Kateri. She might be okay if my mother stayed with her, I reasoned. I looked at Juliette. Maybe she would take a bottle, I considered.

Mama Bear, however, did not like this mousy line of thinking. Leaving my mousy self behind, she marched to the front desk and explained that both of my daughters needed their mother. She demanded permission to keep the baby in the room.

The nurse behind the desk stared at me grimly, but Mama Bear stood her ground. Prickly tension hung in the air between us. At last, she glanced sideways at some of the other nurses who had gathered around her desk, and then turned back to me.

“Do whatever you think is best,” she sighed.

We can't predict the ways in which our children will change us. The responsibilities of parenthood quickly expose our weaknesses and challenge us to improve ourselves. My transformation from mouse to bear is a clear example of the way in which God provides us with grace and strength, skills and abilities, according to our place in life. We need never doubt our ability to do God's will as “for God all things are possible” (Matthew 19:26).

I don't know if the Mama Bear in me will retire when my children are grown. I might return to my old ways of thanking police officers for traffic tickets and smiling at people who cut in line at the post office. In the meantime, however, put out that cigarette, watch your language and, for goodness' sake, don't drive so fast.

I am Mama Bear. Hear me roar.

Danielle Bean writes from Center Harbor, New Hampshire.