I walk through them with my dog and my legs, I find ticks.

I mulch my lawn and I do not find ticks.

When fall or winter weather goes below freezing, the ticks become inactive and hunker down under the leaf litter for protection. But during warm spells even in mid winter they can re-activate, which was apparently what happened in your situation.>

https://www.caryinstitute.org/news-insights/feature/ticks-winter-your-questions-answered#%3A~%3Atext=When+fall+or+winter+weather%2Cwhat+happened+in+your+situation.

I’m mulching them because it seems like the most common insect wintering in my leaves is a tick.