Malleys originally from Patrickwell moved to Murroe in the early 1800s

I have traced my Murroe Malleys as living in Patrickswell in about 1800, but then they all moved to Murroe and married people there.  I was told by my cousin that the Irish didn't move like this at this time and they stayed in one place.  However, I found in one of the marriage records that the priest recorded that Maria Maley came from Cappagh and when I looked into it, I found her baptismal record and the rest of the people I was searching for in my lineage.  Does anyone/someone know why the whole family would have moved to a new location and taken the whole family with them?  My last record shows that John Maley (17 Nov 1801) and Catherine Aherne (5 Jun 1805) were born in Patrickswell but were married in Murroe/Boher (14 Feb 1825).  There were no record of Malleys in Murroe before a slew of baptisms of Malleys starting in 1814 and a slew of marriages starting in 1819.  

I appreciate any help or insight anyone can give me.  What was happening in Murroe in early 1810s that would bring the Malleys to the area?  I don't want to assume anything.  If I am wrong, please feel free to correct me.  I appreciate any answers.

Also, to Roger:  thank you for steering me to RootsIreland.ie.  I have found the service invaluable!

Thank you,

Dawn Tobin