Every 13- or 17-years a remarkable event of nature happens - cicadas emerge from more than a decade underground. How do they keep track of time? This is one of the “seven biological wonders of the world,” according to John Cooley, a biologist at the University of Connecticut.

“Seventeen [years] is just an inordinately long time to keep track of anything,” adds John Lill, an insect ecologist at George Washington University. “I can’t keep track of five years let alone 17, myself—so how an insect does it is pretty remarkable.”

During their long stint underground, the insects sip at xylem sap, the nutrient-poor but water-rich liquid that moves from a tree’s root tips up to its canopy. Each year as a tree buds and blossoms, its xylem is briefly richer in amino acids, leading one team of researchers to call it “spring elixir.” Cicadas appear to count each flush of spring elixir.

Another researcher said, “We know that’s what they count. Where they’re putting their little chalk marks on the wall, we don’t know. We really don’t understand how they’re keeping track of it.”

Possible Preaching Angle:

God’s timetable is even more mysterious. James tells us to “be patient until the coming of the Lord” (Jam. 5:7) Peter adds, “A day with the Lord is like a thousand years, and a thousand years are like a day. The Lord is not slow in keeping his promises” (2 Pet 3:8-9). God’s timetable is higher than ours so we must trust in Him and his perfect timing.