Is it okay if I let you in on a little secret? I found a rats nest behind my parents' fridge when they asked me to look for the rats, but I did not tell them about it
Oh you are serious aren't you? Aren't you? I just wanna know why wouldn't you tell them about the rat's next they asked you to find?
I like rats and this is my way of expressing that
If someone asks you to find something and you do but don't tell them, thats not okay. They were relying on you to do something for them and you are going to let them down. This'll cause them to lose faith in you and turn to someone else whenever they need help.
I'm still going to look for rats when my parents ask me to. I won't tell them about it.
You need to tell your parents as it is their house. You can take the rats elsewhere and not kill them. Just let them know please so they don't have rat droppings all over the place.