I killed a cat once while driving a car. Similar situation; it just came darting right out under the vehicle, and there was no think to think or react before the telltale "thud" and dead cat. Honestly, theres nothing you can really do when an animal decided to sprint directly across the pavement, and though you may experience some remorse over the incident, you kind of have to realize it had everything to do with the animal's actions and little or nothing to do with yours. Granted, animals can't reason about traffic, but it's still not your fault.
Interestingly, that cat is just one of quite a "life list" of road kills I have. In fact, I am a bit of a legend in my family, as wildlife seems to be drawn to the sound of my tires like a siren song. Here are the other victims I can recall off the top of my head: two deer, multiple raccoons, opossums and groundhogs, a dove, an owl (swooped right down into my front grille in the dark when I was a teenager), a squirrel and probably a couple more critters I am forgetting. I guess this is the hazard of living in rural areas where animals are seen near the roads on a daily basis. I also have a pretty strict philosophy about what to do when an animal decided to make a last-second dash across the roadway. I DO NOT slam on the brakes or swerve violently in an effort to avoid them. I figure there's a good chance of me ending up in a ditch or otherwise if I do. I'll hit the brakes and make a modest steering attempt to avoid them, but ultimately, I'd rather kill a critter than kill myself or wreck my vehicle.
Now, if that happens on my scoot, who knows what I'll do. One thing I can tell you is that I am MUCH more mindful of wildlife when driving my scooter. There are TONS of deer in my area, and in the evenings, they are everywhere along the local back roads. I know where they like to hang out, and whenever I am driving my scooter at that time of day, I go very slowly through those areas and watch closely. Last evening was a perfect example: I was probably within 20 yards of five or six deer during the course of my rise. With the scooter being so quiet, you are often quite close before they realize you are there, and there's no telling which way they'll choose to run when panicked. I figure any direct hit between my scooter and a deer will have all three of us (scoot, myself, deer) on the pavement, and that's an ending I'd very much like to avoid.