When the other two burners lit, there was a thumping / thrashing sound from inside the grille .
I moved about 5 steps back from the grille, not knowing what was happening .
I saw something fall out of the bottom of the grille, still smoking .
About 5 seconds later, a rat run up the block wall that divides the property next door, it stopped on the top of the wall for a few seconds, with all the hair / fur singed off !!!!!!!
First 'roof rat' I've seen in years in the backyard .
All of the bait stations are back out in the backyard full of fresh bait .