The InTice 10 Perimeter Bait has a shelf life of 1-year if opened, and 3-years if not opened.
Yes, as long at the area under your mobile home stays dry you can use the InTice 10 Perimeter Bait, and it should provide up to a 90 day residual.
Intice 10 will not work for springtails due to their feeding habits. We would recommend trying a dust such as Delta Dust in and around all of the cracks and crevices where you are seeing activity. Delta dust is a good choice because it works even if it gets damp and it lasts up to 6 months. We would further recommend that you treat the exterior of your home with Talstar P. Pull back any mulch, straw or plant bedding at least 6 inches from your home. Make sure your gutters are in good condition and are not causing water to pool against the structure.
Spraying an insecticide over areas where you applied InTice 10 Perimeter Bait would contaminate the bait rendering it to be ineffective.
You will need to wait atleast 7 days after the Intice 10 Perimeter Bait was applied to treat the exterior perimeter foundation of the home. If wanting to continue also using the bait, start the periemter band where your spray application stops out from the foundation.