Some humans might be considering the experience of the intended target of the control device.

Leaving mammal traps unattended is cruel whether in the woods or in the home. If I check my traps every 8 hours or so, I'll be sure to find and kill any mice long before they start gnawing off limbs. Although, personally I just use the spring traps for mice, and leave the glue traps for crickets. Possibly this is cruel to the crickets...