My daughter and son ate silica gel?

What should I do? my daughter and son ate the silica gel that is in a small packet. I was ing and they were watching tv. Then she came and told me that she ate small things. I didnt know what is that small thing!! when I discovered that they Open the silica gel small packet and they were eating it! I dont know how much they ate, she said only one piece ! wat should i do ??