Bedtime Science: Daddy longlegs – calling a spider a spider

Welcome to the second instalment of Bedtime Science.

I reckon if you’re reading this for yourself you’re old enough to have a look at the stuff in brackets. If you’re reading it to a little person you can happily skip what’s in the brackets.

Daddy longlegs!

There are at least two very different types of minibeasts called daddy longlegs. They all have eight long legs, which is where they get their name. One is a type of spider and the other is not a spider. You’ll have to remember that the harvestman is another name for the type of daddy longlegs that is NOT a spider or this story is going to get confusing.

When I was a University student I was learning about minibeasts and I had to collect some. I needed two different types of arachnid. Spiders are arachnids but there are also other types of arachnid. I could easily get a spider but I needed one other type of arachnid too.

(Minibeasts are small animals without backbones – scientists call them invertebrates.)

The harvestman is one of those other types of arachnid and I decided I’d get one of them. Mites are so small you can hardly see them. I thought a scorpion would be too hard to find. But finding a harvestman turned out to be harder than I thought.

My Granny heard that I needed a daddy longlegs. She told me she had plenty and I could come and get one. That was a relief. But when I went over I found she had these:

This one's on my bathroom ceiling.
This one’s on my bathroom ceiling.

That was disappointing. People do call this a daddy longlegs but it wasn’t the right type of daddy longlegs. The type I wanted doesn’t have a web but this one did so I knew it was a spider.  I didn’t need another spider.

The little round blob on the top of the body in the photo is an egg sac, so this is a female.

(Spiders have two separate body segments – a separate cephalothorax and abdomen. In harvestmen the cephalothorax and abdomen aren’t distinct so it looks like they only have one body segment. And they don’t have a web.)

(Some helpful information from the Australian Museum also tells me it’s probably a Pholcus phalangioides, which is one of the most common household spiders in Australia, where I live.)

Pholcus phalangioides with egg cocoon from Source: picture taken by Olaf Leillinger on 2005-08-26 License: CC-BY-SA-2.5 and GNU FDL.

Above is a very nice close-up picture and you can see the egg-sac really well. You can even see the bristles on her legs.

Daddy longlegs - the harvestman type
Daddy longlegs – the harvestman type

I accidentally brought this elegant harvestman into the house yesterday. This is the type of daddy longlegs I’d wanted all those years ago. You’re seeing double because the strong light is making a strong shadow.


I only had my phone to film it so the quality’s not so good but you can see it feeling  its way with its legs.


(The pair of legs behind the front legs is used by harvestmen to explore their environment.)


I never did get the right type of daddy longlegs – I had to make do with a very tiny mite. I don’t know if my tutor could even find it in the collection jar but if not he believed me anyway!

(Scientists like to put living things that are similar into groups. Spiders make up one Order called Araneae. All the different types of harvestmen are in another Order called Opiliones. Similar Orders are put together in a larger group called a Class. Spiders, Harvestmen, mites, ticks and scorpions belong together in the Class Arachnida – arachnids. Arachnids, insects and some other Orders are in the Phylum Arthropoda, and guess what the next highest group is? The Kindom Animalia is – you guessed it – all the animals.)

(Scientists give every living thing they know about its own unique scientific name. The scientific name has two parts – genus and species. The scientific name for the spider in the photo is Pholcus phalangioides. Notice how the genus name always starts with an UPPER CASE letter and the species name is all lower case. The scientific name is written in italics or underlined. “Daddy longlegs” is what we call a “common name”. Different people might know the same animal (or plant) by different common names. Or the same common name might be used for a few different animals. This is why scientific names are useful. They can avoid confusing a harvestman with a spider. Or to put it another way, they can avoid confusing a daddy longlegs with a daddy longlegs.)