Corral double gate

Today, the second time in a week, I discovered the cattle had been trying to open the double gates between the corral and the NE pasture.  Why?  There is just snow on the other side of the gates.  The bar is on the other side of the gates, yet the cattle find a way to slide the bar.   If you look lower you see I also have a short chain wrapped around the gates.  A backup way to secure the gates.