The devious plot against the Pandavas

When the Pandavas decided to go to Varanavata to participate in a festival per the suggestion of Dhrtarasta, Duryodhana plotted an attack to kill the Pandavas. He instructed Purocana, one of the ministers, to set fire to the Varanavata house the Pandavas were living in while they were sleeping. When they reached Varanavata, the Pandavas were somewhat suspicious of the house and their safety (although they were not aware of the plot against them). Therefore, they constructed an underground exit incase a fire did occur. My question is, if the Pandavas were doubtful of their safety, why did they choose to stay in Varanavata and why did they not leave that particular house and live somewhere else which seemed a little less suspicious?