Have you ever wondered if animals can communicate to each other and if so how? Researchers have found that in fact animals can communicate to one another. They not only can communicate on a verbal level but also through high frequency sounds, which are seemingly silent. As noted in the book, animals communicate for both mating and expressing aggression. Similar to how honeybees have the "waggle dance" to communicate their feelings and expression, many other animals in the world both large and small have their own unique ways of communicating. Studies found that, "Whales, dolphins, domestic cats, rats and mice, and some bats also communicate with very high frequency sounds" (Pierce). 
Many people wonder how animals that appear to be mute communicate. Pierce's study showed that although they might appear to be mute, in reality these animals are producing a sound at an extremely high pitch. Humans are not able to hear these pitches because of their extreme frequencies. I think in future studies researchers are going to discover not only that animals are communicating but also what they are actually saying to each other. This may take decades, but I think with our advancing technology we will, someday, be able to accomplish this feat.
Sources:
http://www.psychologytoday.com/blog/all-dogs-go-heaven/201202/animal-talk-and-the-need-quiet
Reading this blog made me think to how dogs are trained, with the high pitched whistles. By using these, we are communicating with them. Is it therefore possible for us to also communicate with rats and mice, cats, and bats? Im sure if we cannot now, we will be able to soon. I obviously don't have much experience in the field but is this how we also train dolphins? I am intrigued!