Reporting
We plant our squash seeds in

We plant our squash seeds in mounds from the start.  Once the seedlings are 2 inches tall, you can add mulch. And feel free to add more mulch as they grow.
This "may" help with the squirrels.  The only real defense for small critters is a fence. Also, you can use safe repellents when the seeds are young and vulnerable. Ingredients in repellents may include animal predator urine, blood meal, garlic, sulfur or hot pepper, among others. Spray around your vegetables, not on them. Once the plants are past the tender seedling stage, they tend to fare better.