Groundhog tunnels can sometimes be extensive, with 25 feet to 40 feet of tunnels, some as much as 5 feet deep, and a few chambers. Is this crawl space directly underneath your home? If so, it might be best to have a contractor take a look at it. Concrete pumping companies can fill in deep holes in and around the foundation with a special mix (the service is found under various names, such as pressure grouting). If you do not think the hole is a problem to your home, then there are mixes that you can buy that are specifically for filling in animal burrows/tunnels. You can search online for options, or your local hardware store might know.
Groundhog tunnels can sometimes be extensive, with 25 feet to 40 feet of tunnels, some as much as 5 feet deep, and a few chambers. Is this crawl space directly underneath your home? If so, it might be best to have a contractor take a look at it. Concrete pumping companies can fill in deep holes in and around the foundation with a special mix (the service is found under various names, such as pressure grouting). If you do not think the hole is a problem to your home, then there are mixes that you can buy that are specifically for filling in animal burrows/tunnels. You can search online for options, or your local hardware store might know.