I hope your tank is large enough for the 7 or 8 inches of fish you have in there. (1 inch of fish needs 1 gallon of water). Shortage of oxygen will cause fish to go to the top/surface for air. However Guppies (Poecilia reticulata) are naturally surface feeding fish so that is where I would expect them to spend most of there time. Surface feeders are easy to recognise simply by looking at the construction and shape of the fishes mouth. Note that it tends to open in such a way as to skim the surface of the water.
Guppies can sense a rapid change of conditions in their environment and will normally respond by swimming in a hyper speed.
Fries (the term for baby guppies), are eaten by older guppies, but guppies are eaten by fish like tuna.
What are guppies
Only guppies breed with guppies naturally.
No, guppies are fish.
Guppies do not migrate.
Guppies are compatible with Bristlenose catfish, the bristlenose being one of a few catfish that can live with guppies because of the guppies' water.
Guppies are guppies are guppies. Tiger just describes their colouring/markings. They are the same in temperament as any other guppy.
The plural of guppy is guppies. The plural possessive is guppies'.
Guppies do not precipitate. Rain does.
Guppies phylum is Chordata
Guppies are livebearers. So they don't lay eggs. Male guppies WILL eat their own baby guppies. They will eat any baby guppy they see. It doesn't matter if it's their own or some other guppies'. Male and female guppies eat baby guppies.