Huntah, a COVID-sniffing canine, is welcomed to a Massachusetts elementary school. Scientist-in-residence Regina Barber talks with NPR science reporter Ari Daniel about how a specialized K-9 unit is helping keep kids in classrooms.For more of Ari’s reporting, check out “Dogs trained to sniff out COVID in schools are getting a lot of love for their efforts. You can follow Regina @ScienceRegina on Twitter and Ari @mesoplodon_ on Instagram. Short Wave@NPR.org