It can tick and cause an alarm (false alarm). In fact the OP may be able to hear it if it's ticking. If it's not, then maybe it will be OK to leave it there. I think it's best to take the battery out of checked items if that is possible though. Sometimes movement dislodges something and cause a bit of an unexpected situation. Additionally, non-moving physical items (i.e. no battery) may withstand impact from baggage handling a bit better.