Q.Are these insects squash bugs and eggs and what do I do?
They’re only on my squash and I have treated the entire garden with 5% Sevin dust once about 5 days ago.

Certified GKH Gardening Expert
Yes!
Young squash bugs, or squash bug nymphs, are gray and have black legs. They move quickly and often in groups on the undersides of leaves.
Neem Oil is a good treatment.
https://www.gardeningknowhow.com/plant-problems/pests/insects/squash-bug-control.htm
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm