Its better to have a garden or pots with lots of different flowers, so that you can feed them natural nectar without changing their habits but if you don't have a gardon or flowers...you can use rippen fruits like bananas, pineapple, apples, honeydew etc... things which contains sweetness...but alway remember to feed them organic fruit/flower means without chemicals or preservatives....own garden grown with organic manure are best....

Butterflies feed primarily on nectar from flowers, using their long proboscis (tongue) to sip the liquid. In addition to nectar, adult butterflies also feed on rotting fruit and tree sap.

If you want to feed a butterfly, you can provide a shallow dish or plate with a mixture of sugar water (1 part sugar to 4 parts water) or overripe fruit.

It's also important to note that adult butterflies only live for a few weeks to a few months, so providing food for them may not be necessary for long-term survival.