Butterflies feed primarily on nectar from flowers. Some also derive nourishment from pollen,[23] tree sap, rotting fruit, dung, decaying flesh, and dissolved minerals in wet sand or dirt. Butterflies are important as pollinators for some species of plants although in general they do not carry as much pollen load as bees. They are however capable of moving pollen over greater distances.[24] Flower constancy has been observed for at least one species of butterfly.[25] As adults, butterflies consume only liquids which are ingested by means of their proboscis. They sip water from damp patches for hydration and feed on nectar from flowers, from which they obtain sugars for energy as well as sodium and other minerals vital for reproduction. Several species of butterflies need more sodium than that provided by nectar and are attracted by sodium in salt; they sometimes land on people, attracted by the salt in human sweat. Some butterflies also visit dung, rotting fruit or carcasses to obtain minerals and nutrients. In many species, this mud-puddling behaviour is restricted to the males, and studies have suggested that the nutrients collected may be provided as a nuptial gift along with the spermatophore, during mating.[26] Butterflies use their antennae to sense the air for wind and scents. The antennae come in various shapes and colours; the hesperids have a pointed angle or hook to the antennae, while most other families show knobbed antennae. The antennae are richly covered with sensory organs known as sensillae. A butterfly's sense of taste, 200 times stronger than humans,[27] is coordi

ated by chemoreceptors on the tarsi, or feet, which work only on contact, and are used to determine whether an egg-laying insect's offspring will be able to feed on a leaf before eggs are laid on it.[28] Many butterflies use chemical signals, pheromones, and specialized scent scales (androconia) and other structures (coremata or "hair pencils" in the Danaidae) are developed in some species. Vision is well developed in butterflies and most species are sensitive to the ultraviolet spectrum. Many species show sexual dimorphism in the patterns of UV reflective patches.[29] Color vision may be widespread but has been demonstrated in only a few species.[30][31] Some butterflies have organs of hearing and some species are also known to make stridulatory and clicking sounds.[32] Monarch butterflies Many butterflies, such as the Monarch butterfly, are migratory and capable of long distance flights. They migrate during the day and use the sun to orient themselves. They also perceive polarized light and use it for orientation when the sun is hidden.[33] Many species of butterfly maintain territories and actively chase other species or individuals that may stray into them. Some species will bask or perch on chosen perches. The flight styles of butterflies are often characteristic and some species have courtship flight displays. Basking is an activity which is more common in the cooler hours of the morning. Many species will orient themselves to gather heat from the sun. Some species have evolved dark wingbases to help in gathering more heat and this is especially evident in alpine forms