Real-Life Insect Detectives

Tiny detectives are already at work, leaving clues to help crack the case.

In God’s creation, even the tiniest insect has an important job. The Bible tells us, “The Lord has made everything for its purpose” (Proverbs 16:4). From the tiniest fly to the largest beetle, every insect plays a special role.

Some insects eat smaller insects to keep populations under control. Others spread pollen to help new plants grow, and some feed on dead organisms to aid in decomposition. Yes, living creatures die and then decompose or break down, but that was not God’s original design in his creation.

When Adam and Eve disobeyed God’s commands in the garden of Eden (Genesis 3:6), the consequence was disease, sin, and death (Genesis 3:17–19). But God already had a plan! He designed a beautiful process called decomposition, which recycles nutrients back into the soil. And it is through the process of decomposition that insects reveal clues to solve crimes. Let’s learn how they are truly insect detectives!

What Are Forensic Entomologists?

Entomology is the study of insects. An entomologist can be an exterminator who sprays your house for termites or someone who inspects the food supply for insect contamination. But a forensic entomologist is different. They are detectives who use science to answer important questions like how long ago someone died or whether the body was moved from one place to another.

The time between someone’s death and when their body is discovered is called the PMI (post-mortem interval). And insects help entomologists figure this out!

How Insects Help Solve Mysteries

Everything in God’s creation has a pattern and order. Insects arrive at crime scenes in predictable patterns. Certain insects are attracted to specific stages of decomposition. Some arrive within 10 minutes of death, others not till four months or even three years.

Order	Insect	Stage of Decomposition	Time Since Death
1	Blowfly	Fresh	0–3 months
2	Beetle	Smelly	3–8 months
3	Carrion Beetle	Dry	1–3+ years

Since different insects come at different times, a forensic entomologist uses this insect timeline to determine when the death happened.

God’s Design in Insect Life Cycles

God created all living things with a life cycle. Because God created this order in the universe, scientists can study, measure, and predict the life cycles of insects. This is the life cycle of the first responder, the blowfly.

1. When a female blowfly detects the scent of decomposition, she immediately begins to lay eggs in openings like a nostril or mouth.
2. The eggs hatch into larvae.
3. The larvae will eat and grow, eat and grow, and eat and grow. Scientists call these stages instars.
4. Each larva will then create a cocoon or pupa. While in the pupa, a full change called metamorphosis occurs. The blowfly will transform from a squirming larva to a flying adult.
5. When the adult insect breaks out of the pupa, a new life cycle begins. The life cycle for the blowfly, at 70 degrees Fahrenheit, is approximately two weeks.

At 70 degrees Fahrenheit, each stage in the life cycle takes a known amount of time to complete (time is shown as if this were a blowfly).
Alan R Walker, CC BY-SA 3.0, via Wikimedia Commons // Text added

Insects at all stages of growth are collected from the crime scene. And then scientists use a very important clue—the ambient temperature! Temperature determines how fast insects grow. This is a unique biological clock that God built into his creation.

For example, if the temperature is 90 degrees Fahrenheit, the blowfly’s life cycle is only 4–5 days. But if there are cold temperatures, the life cycle is slowed down (or lengthened). In the winter, the life cycle could be anywhere from weeks to months.

Small Creatures, Big Purpose

You might be wondering, “Why would I want to study insects at crime scenes?” Forensic entomologists use the science of insects to help bring justice. They use God’s order and design in creation to reveal the truth. Everything God created has value and purpose (Proverbs 16:4), and even the life cycle of tiny creatures reflects the glory of God. Next time you see a fly or beetle, remember that you are looking at one of God’s insect detectives.

Do you have a question about forensics or how forensic scientists pursue God’s desire for justice? Ask your parents to help you submit your question today!