In recent years, ambient assisted living (AAL) has studied and a demand for services that monitors living environments to reduce the burden of nursing care has increased. Therefore, we propose an approach of nonverbal human-robot communication for AAL applications based on an attachment behavior model for a mobile robot. This can sense the situation within the environment in real time with less burden on the user. We use an etho-robot as the user interface of an AAL system for useful monitoring services. The etho-robot mimics dogs' attachment behaviors and can provide less stressful communication between humans and robots. In addition, we design behavior for providing notification about a person's status for the etho-robot. The integration of a mobile robot as a user interface of the AAL system will make the communication spatially flexible. We conducted an experiment to evaluate whether humans can correctly recognize the attachment behavior of the etho-robot when the robot performs its notification function. We discuss the usefulness of mimicking a dog's attachment behavior when the robot has such a function.