What activities can you recommend for toddlers so they won't get bored just watching TV/Youtube and playing their usual toys?

Living in a busy area of the city, I don't let them outside. Every sunday we go out to parks or malls. But when we are home my boys have chores, like feeding our pets (6 dogs, hamsters, hedgehogs, snails, turtle and a frog). We also buy books when I need them to sit quietly. We also do tons of mini experiments or crafts.