A pulga e o carrapato ficam no pelo.

Because the subject is a pulga e o carrapato = the flea and the tick. Two singular nouns joined by e form a plural subject, so the verb must be plural too.

• fica = singular
• ficam = plural

So A pulga e o carrapato ficam... is the correct agreement.

Those are the definite articles, and they must match the gender of each noun:

• a pulga because pulga is feminine
• o carrapato because carrapato is masculine

In Portuguese, each noun normally keeps its own article, so you say a pulga e o carrapato, not just one article for both.

Portuguese uses articles more often than English does. In many cases, Portuguese prefers a/o/as/os where English might use no article or a different structure.

Here, a pulga e o carrapato can refer to specific animals, or it can be part of a simple descriptive sentence where Portuguese naturally includes the articles.

If you removed them, the sentence would sound unnatural in normal Portuguese:

• natural: A pulga e o carrapato ficam no pelo.
• unnatural here: Pulga e carrapato ficam no pelo.

Ficam is from the verb ficar. In this sentence, it means something like:

• stay
• remain
• are found
• sometimes even live depending on context

So here ficam no pelo suggests that fleas and ticks stay or are found in the animal’s fur.

This is not the become meaning of ficar, even though ficar can also mean to become in other sentences.

Both verbs can relate to location, but the nuance is different.

• estar often just states where something is right now
• ficar often suggests staying, remaining, or being habitually found somewhere

So:

• A pulga e o carrapato estão no pelo. = they are in the fur right now
• A pulga e o carrapato ficam no pelo. = they stay in the fur / are typically found there

In a simple teaching sentence like this, ficam works well to describe where they tend to be.

No is a contraction of:

• em
  • o = no

So no pelo literally comes from em o pelo, but Portuguese contracts it to no pelo.

Depending on context, no can mean:

• in the
• on the
• sometimes at the

Here no pelo is best understood as in the fur or on the fur.

Here, pelo is a noun meaning:

• fur
• hair on an animal
• body hair

It is different from cabelo, which usually means the hair on a person’s head.

So for animals, pelo is the natural word:

• o pelo do cachorro = the dog’s fur
• o pelo do gato = the cat’s fur

Yes. Pelo can also be the contraction of:

• por
  • o = pelo

That can mean by the, through the, or along the, depending on context.

So Portuguese has two different pelo forms:

• o pelo = the fur / hair
• pelo = by the / through the

In no pelo, it must be the noun pelo, because no already contains the article o, so no pelo means in the fur.

Because pelo and pele mean different things:

• pelo = fur / hair
• pele = skin

So:

• no pelo = in the fur / on the hair
• na pele = on the skin

For fleas and ticks, no pelo is very natural when talking about where they are found on an animal. Na pele would focus more directly on the skin itself.

A simple Brazilian Portuguese approximation is:

• a pulga = ah POO-gah
• e = ee
• o carrapato = oo kah-hah-PAH-too
  
  • the rr in Brazilian Portuguese is often like an English h sound
• ficam = FEE-kung with a nasal ending
• no = noh
• pelo = PEH-loo

A more natural rhythm for the whole sentence is:

a POO-gah ee oo kah-hah-PAH-too FEE-kung noh PEH-loo

As written, it most naturally sounds like one flea and one tick: the flea and the tick.

If you want to talk about them more generally as a class, Portuguese often uses the plural:

• As pulgas e os carrapatos ficam no pelo.

That sounds more like Fleas and ticks stay in the fur in a general sense.

Still, beginner materials sometimes use singular forms in simple example sentences, so context matters.