When walking in rural England in spring, sometimes you can find a sign "Lambing!" on gates or fences. It refers to the time when sheep give birth to lambs.
Hall Hill Farm in Durham has its annual Lambing Live Open Day in late March or early April. The farm is open for visitors from 10:30 am to 5 pm showing the lamb births as they happen. The kids would definitely enjoy seeing newborns with their moms in the maternity barn. Similar experiences are offered at Coombes Farm in Lancing, Sussex, Saddlescombe Farm in West Sussex, Gaston Farm in Slindon, and Pitney's Glebe Farm in Langport, South Somerset.
Lambing is a busy time for any farmer that lasts from late winter till late spring. It's also a lovely time for kids! Reward them with a visit to a farm to see nature's work for themselves. You can even participate in bottle feeding the lambs. You can clench them, pat their soft swirled wool. Lambs are very attentive and watch the visitors intently. They often run in pairs. Adult lambs are not particularly shy, but they won't allow you too close.