Silica Gel Packets are used as a Desiccant (moisture removal) and are most often found in packaging for shoes, electronics, medications, clothing and food. While the gel itself is inert and non-poisonous it can cause a stomach upset with diarrhea and vomiting as the most common reactions.
More importantly pets are often attracted to the packets that have been used with food or products that have an attractive smell and when they eat them the packet can get stuck and cause an obstruction in the intestine.
If your pet eats one of these then immediately contact your vet, a better course of action is to prevent the problem from happening in the first place and make sure that any item that is not meant to be eaten is kept away from curious noses and mouths.
Keep yourselves and your furry family members safe.