The main reason why I purchased a grill guard is for the very reason above - a Monarch Butterfly stuck and smacked right on it. When I replaced my radiator 5 years ago, I found a bunch of insects stuck and dead in it which prompted me to purchase a grill guard immediately.
I took my Jeep(TJ) out and treated it to a nice mud bath this weekend. I’ve had my TJ for 6 years and took it out 4 wheeling at Hollister for the first time. I had a blast. They've got trails for different levels from beginners to expert and play areas to test the durability of your car. With the exception of tires and a header, my TJ is stock.