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Butterflies lay their eggs either singly or in batches, on or near the foodplants that will be used by the caterpillars. Many species lay their eggs away from the foodplant, on dry grass stems, dead leaves or even on soil. This strategy prevents the eggs from being accidentally devoured by grazing animals. It also makes it more difficult for parasitoid wasps and flies to locate the eggs.

Some species, e.g. the Marbled White Melanargia galathea, drop their eggs randomly as they fly amongst tall grasses, but most species have very precise requirements. Pearl-bordered Fritillaries Clossiana euphrosyne for example lays their eggs singly on dead bracken or dry grass stems that are within a metre of their caterpillar's foodplant, dog violet. The White-letter Hairstreak Satyrium w-album is even fussier, always laying it's eggs on elm twigs, at the precise point where the new year's growth and old growth meet.

Silver-washed Fritillaries Argynnis paphia lay their eggs in chinks on the bark of oak trees, but the larvae don't eat oak - they begin by eating their own egg-shells, and then go into hibernation until the following spring, when they descend the tree trunks to feed on the leaves of nearby violets.
In the tropics eggs are often glued underneath the leaves of trees and bushes where they are protected from rain and from the desiccating effects of hot sunshine. In the Amazonian rainforests Heliconiine butterflies often lay their eggs on Passiflora tendrils, presumably to place them as far out of the reach of marauding ants as possible.

Orange tip caterpillars Anthocharis cardamines normally feed on cuckoo flower or garlic mustard leaves, but if they encounter another caterpillar they become cannibalistic. It would therefore be wasteful if more than one egg was laid on each plant, so the butterflies have evolved the ability to detect eggs that have already been laid by other females. Studies have shown that many members of the subfamilies Pierinae, Heliconiinae, Danainae and Papilioninae have this ability, and avoid laying on plants carrying eggs laid by other members of their own genus or species.