"Please, I just want to go home!" 
 The bug appearance is the least sympathetic the aliens could ever have. Think of the "starship troopers", the most famous military science fiction action films. There, "The Bugs" are an extraterrestrial race that wants to kill the brave soldiers, to eat their brains and to conquer Earth. 
 Nobody likes cockroaches and insect-like creatures. They are the nightmares for many people including me. 
 So the author challenged her readers. Could she make these weird looking aliens lovable, sympathetic, sensitive, fighters who are trying to survive in a hostile environment? 
 Her aliens are tall (7 feet approximately), humanoids, their outer shell is hard and they look like bugs. They can even reproduce with egg farms. 
 20 years ago their spaceship crashed on Earth and because they were ugly for the human standards, everybody thought that they were hostile or stupid or both. 
 It was the perfect opportunity for some evil men to steal their technology and take advantage of them. 
 So they put them in camps all over the worlds that looked like favelas in Brazil and smelled like rubbish dumps in India. Because the aliens were like cockroaches and cockroaches must (NEED TO) be surrounded by garbage. 
 I suppose the new established refugee camps in Europe will be a close approximation very soon, if people keep being packed there continuously. 
 Author wins her bet. The aliens won't just be tolerable. They will be likable. 
 The main male alien character Sanford (or Nk'os'a'knko really) is a hero, a military man, an inventor who has been waiting 20 years until he is ready to escape and bring help. He is also an affectionate father and a true gentleman. 
 The little alien boy, Sanford's son, named T'aki is adorable, cute and clever. He has never seen his planet. His home, his whole world is Cottonwood. A whole generation of young aliens actually has been born, grown up, learn to live in garbage and they have never seen their true home. Children of a lesser God. 
 The main female human character, Sarah, might look a bit naive, but she is destined to do great things. She will be the catalyst in order things to be changed. 
 The two main characters' relationship will be sweet and kind. They will learn to love each other and please each other. And they will naturally fall in love - although Sarah will never see it coming. 
 The secondary alien characters will be mostly appealing: John Byrnes, Hancock, Levin, Good Samaritan, Che Baccus etc. 
 (Their names are basically nasty little jokes, given by the humans who could not pronounce the aliens' true names. Another way to degrade the poor aliens) 
 The rest of the humans will be unfortunately bad or aloof or clueless. 
 But some (just a few) humans will be truly interested in the aliens' well being and misery. Some of their stories are incredible and may bring you a few tears to your eyes. 
 Concluding I just need to add that maybe this book appears to be Sci-Fi, but it is deeply a political statement with hidden ethical messages.