Don't know what you're mowing with but my lawnmower and tractor have lights on them, and the tractor has a couple of auxiliary lights front and back so I can see what's going on. When it gets HOT during the day, I mow after the sun goes down. More cooler after sundown is more better for mowing.
Sorry to hear your Dad lost his dog. 18 years is a good run for a dog, too. That's always a hard thing to deal with, losing a pet you've had for a long time. Way too close to losing a member of the family.As to the bugs at night and mowing, MOW FASTER!