Can we stop our children from lying?

I reprimanded my Sunday school kids yesterday before I started the day's lesson. As their teacher, I feel responsible of their safety and concern.

Two of the kids, one 6 years and the other 9 years were coming down to the sunday school room without anyone knowledge. The room is located at the ground floor and it's not locked. Any child who is left alone could be the targeted of any kidnappers!

Both of them were lying to me the instance that I asked them.

Both of them denied coming in the room but admitted entering one of the other room. I kept on asking them; the question is that why were you children down here without my knowledge?

The six years old kept denying and defended himself shifting his gaze away from me. His face changed and finally admitted that he came down with the older guy.

I couldn't believe that a six years old lied! Where did he learn that from? His parents are God fearing people that goes to church every meeting and he has a private teacher coming to his house for school lessons.

Which means that he did not mix so much with other kids obviously.

I think the older kid influenced him and taught him to lie.

Ps. Little lies will become big lies...Can we stop our children from lying?