Is there a difference between cicadas and dog days?

There are different insects, one big and one small. The big cicada calls, and the little "Fu Tianer" calls rhythmically. The so-called cicada is what everyone says: the cicada in the sky: that is, it is smaller in size and lighter in color, much smaller than the cicada. They cry differently, too. Know a big, loud one. Futian, a small one, sounds like the word "Futian".