As the power went out in my house (for a good hour) and my aquariums shutdown, I laid in bed watching how my guppies would react to the motionless water that then lacked a light source aside from what was coming in through the windows.
I have 2 guppy tanks in my room, one 10-gal which houses male guppies and the other 10-gal which houses female guppies. The power outage really did not seem to phase the male guppies as they continued their daily mating rituals with the other males in the aquarium. The power outage in the female aquarium however, well that made a big behavioral change...
The females began to group/school together as they sank down to the bottom of the aquarium as if they were ultimately terrified. Their body movements were brief as they moved themselves inch by inch about the tank in search of what was happening. The behavior continued for about half an hour as they began to realize they were all still okay. When I got out of bed they quickly relaxed as they knew I was about to feed them and after that point they no longer seemed afraid at all (to a guppy I suppose I am its means of positive well-being and a sign of their food source).
Overall, this makes me wonder if female guppies are perhaps better suited for survival over the male species. Which wouldn't be all too surprising since females aren't as colorful as males, thus aiding them in camouflage if/when hiding from predators. For more info on that topic checkout this article.
I have 2 guppy tanks in my room, one 10-gal which houses male guppies and the other 10-gal which houses female guppies. The power outage really did not seem to phase the male guppies as they continued their daily mating rituals with the other males in the aquarium. The power outage in the female aquarium however, well that made a big behavioral change...
The females began to group/school together as they sank down to the bottom of the aquarium as if they were ultimately terrified. Their body movements were brief as they moved themselves inch by inch about the tank in search of what was happening. The behavior continued for about half an hour as they began to realize they were all still okay. When I got out of bed they quickly relaxed as they knew I was about to feed them and after that point they no longer seemed afraid at all (to a guppy I suppose I am its means of positive well-being and a sign of their food source).
Overall, this makes me wonder if female guppies are perhaps better suited for survival over the male species. Which wouldn't be all too surprising since females aren't as colorful as males, thus aiding them in camouflage if/when hiding from predators. For more info on that topic checkout this article.
#1 Generally male guppies are much more vibrant and females are duller in color(although I've been breeding my females as photographed here to have more color then a lot I've seen). You may even see your male guppy doing an awkward dance during courtship to show-off these possible colors. 
#3 At the end of the abdomen you may notice an often dark almost circular area which is called the gravid spot, if your fish has one then its a female. The gravid spot tends to change colors from pink to almost black(sometimes a combination of both), the color differs depending if the guppy has eggs inside of her or not. When the female has eggs/fry inside her the under belly will appear fuller and her body more rounded in shape(as seen above) and she may even start to develop a hunched/slumped spinal appearance.
*Note* Some say the dorsal and caudal fins are usually bigger on males then that of the females. Although I believe I've seen some females with a fairly long dorsal fin.