Untiring Love

In order to renovate the house, a man had to tear open the wall. The house had a hollow space between the wooden walls. When tearing down the walls, he found that there was a lizard  stuck there because a nail from outside was  hammered into one of its feet. He sees this, feels pity, and at the same time he is curious. When he checked the nail, turns out, it was nailed 10 years ago when the house was first built.
What happened?

The lizard has survived in such position for 10 years! In a dark wall partition for 10 years without moving, it is impossible and mind boggling. Then he wondered how this lizard survived for 10 years without moving a single step--since its foot was nailed!
So he stopped his work and observed the lizard, what it has been doing, and what and how it has been eating. Later, not knowing from where it came, appears another lizard, with food in its mouth.

Ahh! He was stunned and at the same time, touched deeply. For the lizard that was stuck by nail, another lizard has been feeding it for the past 10 years...

I am short of words. What can we call this? Faithfulness, Love, Devotion?