Davis played in six games for the Colts last season, starting three at middle linebacker late in the year when Gary Brackett was injured. He made 26 tackles.
The Colts claimed Davis off waivers from Detroit before the 2008 season started. He was originally a third-round pick out of Florida State by the Arizona Cardinals in 2007. Davis didn't stick and spent most of 2007 on Detroit's practice squad before appearing in one game in which he recovered an attempted onside kick.
It's unclear if the Texans see him mostly as a backup to DeMeco Ryans in the middle or as a player who could possibly contribute outside.