In recent years Mobile Wireless Sensor Networks have observed a substantial increase in the use of specific applications like surveillance, military applications, disaster management, wildlife monitoring, etc. The wireless nodes are small electronic devices embedded with various sensors to perform the given tasks. These sensor nodes are provided with a limited battery power which is a big constraint for the performance of the network in unattended environments. Also, mobility affects the battery life of the nodes to a great extent. Thus, it is necessary to design protocols to make the efficient use of available energy in the nodes and to acquire complete operability. This problem can be solved to some extent by clustering of the sensor nodes. This paper is a study about constraints of WSN and clustering techniques used for forming the network are presented. © 2019, Springer Nature Switzerland AG.