Wikipedia
Ūsiņš is a deity in Latvian mythology, the god of light and spring, symbol of fertility, guardian of horses and bees.
It is one of few Latvian deities, whose historical sources can be derived to be more or less genuine testimony. With Ūsiņš Day begins summer, Ūsiņš bestows fields with green grass and trees with green leaves, therefore on Ūsiņi guys drove horses to pieguļa for the first time. Ūsiņi coincidences with Jurģi on 23 April (in Gregorian calendar Ūsiņi falls on 9 May), which is the Christian Church's deposit. Ūsiņš has its own ornamental sign, which is similar to two letter E facing their backs against each other. This sign is the most common ornament for gloves. There is a belief, that such gloves grands the wearer with good luck on the road, and such gloves are called atslēgaiņi.
The most important symbol of Ūsiņš Day is a foal, which can be interpreted differently. It is both the power of Dievas, human energy, and a phallic symbol, because sexual power is equal to the creative energy. Yellow foal symbolizes energy from the Sun. With Ūsiņš it is also linked to someone else's image – the golden grass snake, which in turn, a snake is a symbol of energy flow.